弗里茨·哈伯_百度百科

Fritz Haber, Ammonia synthesis by the Haber process Inventor of

Fritz Haber 1868—1934

In the history of chemistry, there was a chemist who, although long since buried, had left the world with a fierce debate about his merits and wrongs. He was Fritz Haber, the world-famous German physical chemist and inventor of synthetic ammonia at the beginning of the last century.

Speak highly of Haber He is an angel who brings harvest and joy to mankind and is made of air Bread Of the saints; Those who cursed him said that he was the devil who had brought disaster, suffering, and death to mankind, and that the contrasting and contrasting assessments of one person were astonishing; What Haber's merits and wrongs are, depends on the brilliant and bumpy road that the chemist took in his life.

The tomb

Haber was born on December 9, 1868 Silesia the Breslau (now Poland the Wroclaw His father was a knowledgeable and well-managed Jew Dye Businessman, hearing and witnessing, the influence of the family environment made him and chemistry from a young age. Haber Gifted with talent He mastered a lot of chemical knowledge at a young age, and he has been to Berlin, Heidelberg, Zurich He studied as a student of the famous chemists Hoffmann and Bunsen. After college Jena University Once engaged in Organic chemistry Studying and writing sensational papers in chemistry, Haber was awarded a doctorate at the age of 19 by the Royal Technical University of Germany, in 1896 Karlsruhe University of Technology While a lecturer, Harper married the beautiful and virtuous Miss Clark in 1901. Haber served from 1906 Physical chemistry And professor of electrochemistry.

From childhood Chemical industry Have a keen interest.

After high school, Haber Arrive successively Berlin , Heidelberg, Zurich Go to college. During his school years, he also worked as an intern in several factories and gained a lot of practical experience. He loved the chemical industry, the great career of Liebig, the father of German agricultural chemistry.

Haber's wife

While in college, Harper was in University of Berlin Hoffman Under the guidance of the professor, wrote an essay on Organic chemistry The thesis, and thus received a doctorate. In 1904, Haber began research after two entrepreneurs promised strong support Synthetic ammonia In 1909, he became the first scientist to produce ammonia from the air. It has freed mankind from the passive situation of relying on natural nitrogen fertilizer and accelerated the development of world agriculture. Harper has since become world famous Great scientist . In recognition of Haber's contribution, Sweden The Academy of Sciences put the 1918 Nobel Prize in Chemistry Awarded to Haber . Due to World War I In, Harper served Chemical Soldier The director of the factory is responsible for research and production chlorine , Mustard gas And used in the war, causing nearly a million casualties. Although according to his own statement, this is "in order to end the war as soon as possible", but this act of Hubble, still by the United States, Britain, France, China and other countries scientists condemned, Hubble's wife Imeva also committed suicide in protest. ^[2]

The First World War ended in Germany's defeat in 1919. For some time after the war, Haber devised a scheme to extract gold from seawater. Hoping to pay for it The Entente countries Demanded war reparations. Unfortunately, in the sea Gold content Far less than people thought at the time, and his efforts could only be in vain. After that, through the reflection of the war, he devoted all his energy to Scientific research Medium. Under his effective leadership, William Physics Institute of chemistry To become one of the academic centers of chemical research in the world. Based on years of experience in scientific research, he pays special attention to creating an unbiased and independent research environment for his colleagues, in which he emphasizes the combination of theoretical and applied research. Thus, his institute became a first-class scientific research unit and cultivated many high-level researchers. In order to change the disgraceful impression left by the war, he actively worked to strengthen the nations Scientific research institution And friendly exchanges between scientists from all over the world. Nearly half the people in his lab come from all over the world. His friendly reception and warm guidance not only won him the understanding of the scientific community, but also increased his prestige. However, tragedy soon struck him again. In 1933 Hitler usurped power in Germany and established Fascism After the ruling, he began to pursue the farce of "Aryan science" with the aim of eliminating "Jewish science." Although Haber was a famous scientist, he was brutally persecuted just like other Jews because he was a Jew. The fascist authorities ordered the dismissal of all Jews in science and education. Fritz Haber, the great chemist, was renamed:" Jew · Haber ", that is, Jews Haber . The William Institute, which he headed, was also reorganized. On April 30, 1933, Haber solemnly declared: "For more than forty years I have chosen my collaborators on the basis of knowledge and virtue, and not on the basis of their nationality and nationality, and for the rest of my life it will be impossible for me to change what I consider to be so sound methods." Then Haber was forced to leave the country where she had served her fervently for decades. First he should Britain University of Cambridge An invitation to work at Bob's lab. Four months later, Harper's Heart disease The attack occurred on January 29, 1934 Switzerland Died.

Although Haber was forced to leave Germany, the German scientific community and people did not forget him, and on the first anniversary of his death, many German societies and scholars ignored him Nazi They organized rallies to commemorate the memory of this great scientist.

Electrochemical reduction

After obtaining the supernumerary lectureship, Haber Take up electrochemistry Research. The first thing he did was nitrobenzene The reducing effect of... This research made him famous. At this time, Hubble's best expertise was still organic chemistry, but at the same time, he was learning new things Physical chemistry Knowledge applied to organic chemistry. L. Gattermann and other chemists, yes Nitro compound Electrochemistry of Reduction reaction Studies have been conducted and a great deal of variation has been obtained Reduced state Product. Research at the time seemed to suggest that these Reduction product The nature and relative proportions depend on electrolyte the Ph (pH) , Current density , power on time and Metal electrode The nature of... consider reduction Be due to Primitive ecology Caused by hydrogen. However, this view cannot explain the huge differences in the activity of the initial ecological hydrogen. In 1898, Haber established Electrode potential The importance of clarifying some misconceptions in electrochemistry.

In accordance with Nernst (H. W. Nernst) theory that the electrode potential of a gas is determined by the electrode of the gas Effective concentration Decided. Haber Realize that the electrode potential consists of anode and cathode gases activity Is determined by the ratio. Published in 1898 about nitrobenzene Electrochemistry of Reduction reaction In the paper, Haber first proposed electrode potential determination Reducing power The higher the electrode potential, reductant The stronger the reduction ability. Early researchers usually used a more constant Current density Gradually increase the potential of the cathode. According to Haber, this amounts to using reducibility Gradually enhance a series of chemical reducing agents, while generating a series of major Reduction product . Haber plans to change the current during electrolysis, at current density - Electrode potential At the turning point of the curve, the potential of the polarized cathode is kept constant, so that the released hydrogen is used to reduce the depolarizer. In order to gradually separate the main reduction products, starting with a low cathode potential, Haber used platinum (and sometimes nickel) as an electrode with a low hydrogen overpotential. He thought, Hydrogen overpotential High electrodes, such as zinc, produce strong Reduction reaction . He took Leggin's advice and used Auxiliary electrode Determination and control of cathode potential using thin-walled capillaries Glass tube The auxiliary electrode is connected to the cathode, thus eliminating the passage electrolyte The electric potential drops.

He used platinum as a cathode for electrolysis at a low potential nitrobenzene The alkali solution, contrary to the original expectation, obtained the main product is Azobenzene oxide . On the basis of Bamberg (Barmberger) A series of studies on nitrobenzene, nitrobenzene With studies of phenylhydroxylamine reduction, Haber showed that electrochemical reduction reactions followed the same steps as ordinary chemical reduction reactions NO 2 (nitrobenzene) →RNO (nitrobenzene) →RNHOH (benzene hydroxylamine) →RNH2 (Nitrobenzene) aniline ), other products come from Side reaction . Azobenzene oxide as the main Reduction product Appear, is due to in Alkaline solution In, Intermediate product Nitrosobenzene and benzene hydroxylamine undergo a dehydrating reaction:

RNO+ RNHOH=RNONR+ H2O ................................................

Haber Proof, whether ordinary Chemical reaction still Electrochemical reaction Both nitrobenzene and benzene hydroxylamine exist, nitrobenzene is a ratio nitrobenzene stronger Depolarizing agent And therefore can only exist in very dilute solutions. However, by Azo dye Fixed color, can be detected nitrobenzene And phenylhydroxylamine. He also succeeded in the electrochemistry of nitrobenzene Reduction reaction , to prepare a large amount of benzene hydroxylamine, the reaction in alkalescence Buffer solution It is carried out with an appropriate high potential to instantaneously reduce nitrosobenzene to benzene hydroxylamine, thereby avoiding formation azobenzene However, the electric potential should not be too high to avoid further reduction. He also discussed the formation of azobenzene, which is also an electrochemistry of nitrobenzene Reduction product . Azobenzene oxide strengthening reduction down-generation diphenylhydrazine . As Haber points out, nitrobenzene Azobenzene is rapidly generated in an alkaline solution by the following reaction:

2RNO2+3RNHNHR=RNONR+3RNNR+3H2O…………

Haber believes that in alkaline solution, with low hydrogen overpotential cathode electrolysis of nitrobenzene, the main product is Azobenzene oxide ; The use of high hydrogen overpotential cathode electrolysis of nitrobenzene, the reduction effect is stronger, to obtain diphenylhydrazine, and finally formed aniline .

Haber also studied the electrolysis of nitrobenzene in acidic solutions reduction It was found that the reaction (1) became very slow, but in a strongly acidic solution, benzene hydroxylamine rapidly transformed into p-aminophenol Diphenylhydrazine transforms into benzidine The main products are p-aminophenol, benzidine and aniline, and the ratio is determined by the concentration of acid.

Haber's success, world attention, became his research in the field of electrolytic reduction and oxidation impetus . In 1898, four years after entering the Technical University of Karlsruhe, Haber was promoted to associate professor at the age of 30. In the same year, he published his first book, The Theoretical Foundations of Industrial Electrochemistry, which further enhanced his reputation. He has established a recognized school of electrochemistry. This was his most creative period, but the constant overwork took its toll on his health. He was so focused on his work that he forgot himself. In the early days of his research career, he sought only brief respite in his small circle of congenial friends. He hung out with teachers, writers and artists, Haber I like to talk with them, but even on such occasions I do not want to rest my mind. In 1902, Haber was sent by the Bunsen Society of Germany as a representative to the annual meeting of the American Electrochemical Society, which can be seen in his reputation. His outstanding talent and rigorous attitude have left a deep impression on his American counterparts. His long lectures at the club were well received by chemists in Europe and the United States. The report was published in the German Electrochimica Acta in 1903 and is considered an outstanding document of permanent value in the history of the electrochemical industry.

Electrode process The nature of

After early electrochemical reduction studies, Haber Start paying attention to Electrode process The essence of the problem. After a series of studies, a general theory is proposed, which applies both to irreversible reduction processes such as nitrobenzene Reduction, but also reversible Reduction reaction Such as the quinine-quinol system. By pair Polarization curve Conducting a detailed study, he believes that the direct ion discharge on the electrode is a very fast process, if it contains slower chemical changes, it must appear chemical polarization, chemical polarization depends on the rate of chemical change to a certain extent. He believed it was a basic theory that could be tested experimentally. For irreversible reduction reactions, hydrogen on the cathode at rest Effective concentration (or solution decompression) and the cathode potential, by the rate of hydrogen consumption on the electrode (=k1 [D] [H] n, where D represents the depolarizer) and the rate of formation (=k2i, where i represents Current density The balance is reached to determine. the Electrode reaction It can be expressed as: D+nH=DHn, and the cathode potential E is obtained expression : E= constant +RT/ (nF) log (D) /i), this formula can well explain the relationship between the three variables E, i and [D], but in quantitative calculation, it must be multiplied by an empirical factor greater than 1 in front of the logarithmic term in order to agree with the experimental results. Haber could not explain it, only tentatively attributed it to the resistance of some kind of electrode reaction. He thought, Constant term Contains the special catalytic effect of the electrode metal. The problem of irreversible reduction has not been completely solved, and the correctness of some assumptions in the Hubble theory is also questionable, but its great role in promoting the development of electrochemistry has been recognized by the world. A few years later, he was right quinine - Reversible quinol system REDOX reaction Interest has occurred and some have been gained Actual value The results of the establishment Electrode process the reversibility Theoretical sum quinhydroquinone The electrode theory. At that time, his main interest was in the nature and nature of electrode processes Reaction rate There is no emphasis on its use for the determination of hydrogen ion concentration. He believed that the symmetrical cathode polarization curve and anode polarization curve were due to the electrode upslow The reaction C6H4O2+2H=C6H4( OH 2 and fast Ionic reaction 2H++2e=2H as a result of the combined action, the slow chemical reaction determines the rate of electrode process. He backed this up with other experiments.

Fuel cell

Like other electrochemists of his time, Haber was right Fuel cell Have a keen interest. In this type of cell, hydrogen, carbon, carbon monoxide or other fuels can produce an electric current through a REDOX reaction at a lower temperature. Because it can take advantage of almost all of the oxidation process Free energy It will undoubtedly have a revolutionary impact on the production of electric energy. Haber was working on fuel cells not for that purpose, but to find a way to measure the oxidation of hydrogen, carbon, and carbon monoxide Free energy of reaction Change the new way. "Jaequel Battery" C︱ 3 NaOH (Molten) ︱Fe (air), caught his attention, began to study this battery. In this battery, the carbon is dissolved carbonate Can produce a stable current, voltage of about 1 volt, generate electricity and carbon Heat of combustion Roughly the same. People speculated at the time, Cell reaction The value is C+O2+2OH-= CO 32-+H2O, iron in pure Sodium hydroxide mediating Hydrogen electrode . Haber After careful research, it was proved that the battery was not a carbon-oxidation battery as originally thought, but a hydrogen-oxidation battery, and the iron actually acted as a reversible battery Oxygen electrode . He replaced iron with platinum and found that it produced the same electric potential as iron. He believes that the potential of the carbon electrode is not determined by the "C→CO32-" process, because Na2CO3 do electrolyte The battery is not working. He found that because of a chemical reaction: C+H2O+2NaOH=Na2CO3+2H2, the reactive hydrogen is released, so the carbon electrode directly acts as the hydrogen electrode. Haber points out that this Hydrogen and oxygen fuel cells the Electromotive force , and the thermodynamics of water formation according to the reaction of hydrogen and oxygen Free energy The calculated values of the equations are consistent. Having discovered the reversible oxygen electrode for the first time, Haber quickly applied it to gas batteries in order to study high-temperature oxidation reactions. By coating it thin with platinum or gold Glass film or Ceramic membrane do Electrode connection Two gases, overcome Fused alkali Caused by the temperature and Gas concentration Limitations, such as batteries: air ︱Pt︱ hot glass ︱Pt︱CO+CO2, electromotive force of about 1 volt, Total cell reaction : CO+1/2O2=CO2 ( Electrode reaction 1/2O2+SiO2+2e=SiO32-,CO+ SiO32--2e= the addition of SiO2+CO2), due to strong polarization This type of battery has little practical value. With this simple but very novel device, Haber was able to determine carbon, Carbon monoxide And hydrogen in Oxidation reaction Hit the mark Electromotive force And calculate the reaction accordingly Free energy The temperature range is not easily reached by other methods. Obtained data with Harper's Thermodynamic calculation The values are basically consistent.

Corrosion of iron

During most of his time in Karlsruhe, Haber was interested in the electrochemistry of iron. The most important research involves the anodic properties of iron and the passivation of iron in alkaline solutions, and discusses the conditions for the quantitative formation of ferrate ions by anodes and its relationship with each other Ferric acid The relationship between root ions. Haber Insist that in the generation ferrate In the case of iron, a layer is formed due to the surface Oxide film Iron is usually passivated. At that time, this passivated oxide film theory was not endorsed by most people. This doctrine relates to passivation of metals Electrode potential Do not match. In fact, passivity It can't last long, and the effects of passivation can be eliminated. After careful research, Haber strongly believed in the oxide film theory. However, it is believed that in the case of porous oxide film, the electrokinetic activity of the exposed metal is changed, and the complete passivation of iron forms a dense oxide film on the surface, the main component of which is the high price of iron oxide It's not in with iron Equilibrium state ; In order to eliminate the effect of passivation, a chemical reaction can be used to make the oxide film into a hollow shape, and the iron can be reactivated. In some cases, the surface of the passivated metal has a layer of visible oxide, such as a concentrated hot strong alkali solution to dissolve this layer of oxide film, the metal Recovery of activity . Haber's study of passivation played a very important role, and his conclusions are basically consistent with today's view. Haber is also concerned about underground water mains and Natural gas pipeline The corrosion problem. In common use at the time Direct current To create a pipeline system Stray current And thus lead to Underground pipeline The problem is very serious and widespread. Although it has been studied by countless people, its essence is still unclear. Haber conducted a tireless search, comprehensively studying relevant factors such as soil composition and soil composition Electrical conductivity The direction and size of the weak underground current, the cathode characteristics of iron in the soil, etc. By digging deeper into this problem, his theory was able to predict the occurrence of such corrosion. Due to use Alternating current His work has lost its practical significance, but it contains many electrochemical research topics of permanent value.

Third law of thermodynamics

1905: Haber's book Industrial Gas Reactions thermodynamics "Was published. It has been hailed as "a model of precision and keen insight" and has played a pivotal role in the history of thermodynamics. He discussed the experimental determination of gas equilibria and Free energy The famous "uncertain thermodynamic constant" problem in the equation, the term "uncertain thermodynamic constant" was also proposed by Haber. In 1904, he became interested in the problem. He said that the free energy of a solid reaction is approximately equal to Heat of reaction . It is difficult to determine because the measurement is imprecise Temperature coefficient . He concluded that if the reaction between solids obeyed Kopp's law, then, Integral constant namely Absolute zero of Entropy change It should be zero. In 1904, Richards (T. W. Richards) found that according to certain batteries Electromotive force Calculate the free energy change, with the reaction Thermal effect Close. Van't Hoff The constant problem was also discussed by J. H. Van 't Hoff. Haber was deeply influenced by Richards' findings and van't Hoff's work. However, due to his limited knowledge of thermodynamics, he could not completely solve this problem. Hubble was very careful not to accept purely theoretical ideas without experimental evidence. He thinks, in Molecular number Not changing Gas reaction If a constant is not equal to zero, its value may also be small. pass Experimental data The results supported his conclusion. He suggested that the integral constant might be slightly larger in gas reactions where the number of molecules changes. The following year, Nernst The heat theorem is proposed. Haber regretted being too cautious and not taking the bold step. Of course, such steps can only be taken by a man with Nernst's keen insight and great talent. but Haber In the study of this issue, still occupies an important seat.

Nitrogen fixation study

In 1904, Haber Start looking at ammonia balance. At that time, he served Vienna Scientific advisor to the Margulies brothers, the two brothers on the new industry Nitrogen fixation The method is very interesting. Through nitrogen and hydrogen Mixed gas Under the action of catalyst, ammonia can be continuously synthesized. However, the maximum yield is always limited by the ammonia balance. Haber decided to study the question first. Chemists have done it Calcium nitride Reduction and regeneration experiments with manganese nitride, however, due to the high temperature required, showed that calcium and manganese could not be used as catalysts. In 1884, Aaron Ramsey (Ramsay) and (Young) tried the heat of ammonia Synthesis method . They found that at 800 ° C, using iron as a catalyst, ammonia never completely breaks down. So they tried to take advantage of it Inverse reaction Synthesize ammonia, but you can't get ammonia. It's usually thought that nitrogen Chemical property Extremely reactive, it can only be hydrogenated at high temperatures, and in fact, the decomposition of ammonia at high temperatures is very thorough.

His first exploratory experiment was the synthesis of ammonia with iron as a catalyst at 1020 ° C. though Haber Fully aware that high pressure is good for ammonia synthesis, he chose a large one anyway Atmospheric pressure Because the equipment required is simple. Contrary to Haber's expectations, the experiment went very well, and the ammonia balance was achieved for the first time. However, the concentration of ammonia is very low, between 0.005% and 0.012%, and it is difficult to choose a figure that is closest to the truth. At the time, he favored the upper limit, but later studies showed that the lower limit was closer True value The high yield may be new Iron catalyst The special role of. The original purpose of determining the equilibrium state of ammonia was achieved, and he described the results of his experiment in these words: "The reaction tube was heated to dark. Red heat Above, at atmospheric pressure, no catalyst, at most trace Ammonia production, even if greatly increased pressure, Equilibrium position Still not ideal. At normal pressure, using a catalyst, the temperature cannot be higher than 300 ° C for practical success." It appears that direct synthesis of ammonia as industry Nitrogen fixation The foundation doesn't seem to have much hope. Haber Drop the issue and end the partnership with the Marguri brothers. In 1906, Nernst In examining the experimental data of gas equilibrium, it was found that in the case of ammonia, there was a large discrepancy between the Hubble data and the heat theorem calculation. Nernst then remeasured the ammonia equilibrium data under high pressure (50 atmospheres), which was used to increase the ammonia concentration and thus decrease it Experimental error . Nernst was the first to synthesize ammonia under pressure. His ammonia was much less than Hubble's data and much closer to the theoretical value, such as 0.0045% at 1000 ° C, Nernst 0.0032%, Hubble 0.012%. In the fall of 1906, Nernst wrote to Haber about the situation. Therefore, Haber and Rossignol used the original method to re-determine the ammonia balance data at one atmosphere of pressure, the experiment is very fine, and the results are in good agreement with the previous value, such as at 1000 ° C, the new value is 0.0048%, and the lower limit of the original determination is 0.005%. It also proves that, as Nernst insists, Hubble's initial near-truth value of 0.012% is indeed too high. Haber with Nernst The differences in the experimental data have been greatly reduced, but not completely eliminated. At a Bunsen Society meeting in Germany in 1907, Nernst presented his stress experiments. In the course of the discussion, Haber withdrew the original estimate of 0.012% and published a new number. Hubble's figure is still about 50% higher than Nernst's. Nernst refused to accept the accuracy of Hubble's new measurements, arguing that at one atmosphere of pressure, ammonia was Equilibrium mixture The concentration in the system is very low, suggesting that Hubble should conduct the study under high pressure to eliminate sources of error. Nernst believes that his data is reliable and consistent with the law of heat.

Haber believed in the accuracy of his data, and saw Nernst's opinion as a great disgrace to him, and felt that his honor had been compromised. Haber And Rosegel immediately re-determined the ammonia balance accurately. This time, the experiment was conducted at 30 atmospheres. Their device is very simple, but serves the purpose of the experiment extremely well. Through the thermal decomposition of ammonia, a mixture of nitrogen and hydrogen is obtained, which is passed through a catalyst containing iron or manganese Thick wall Quartz tube . The equilibrium mixture is then quickly removed for cooling analysis. Harper based it on new data Free energy The equation shows that the yield of ammonia can be high enough to be suitable for industrial purposes, but the conditions are harsh and difficult to achieve. For example, at 600 ° C, 200 atmospheres of pressure, ammonia Conversion rate Up to 8%. But at that time compressor What can be achieved Maximum pressure That's 200 atmospheres, no large-scale chemical operation has ever used such a high pressure, and the best catalysts (iron, manganese, nickel) are much less active at 700 ° C. Therefore, if the obstacles of catalyst and high pressure are overcome, it will undoubtedly open up an industrial synthesis of ammonia Bright path , Nitrogen fixation The problem will be solved. Haber He accepted the challenge because he had the help of his close and ideal partner, Rosegel. The high-pressure technique was soon used in the Karlsruhe laboratory and was improved by Rosegel. Rossegel was renowned for his dexterous, first-rate experimental skills. Work began in 1908, when they designed and built one converter It is installed in a steel high-pressure bomb and can operate normally at 200 atmospheres. All we need is a more active catalyst. After a long exploration, it was found that below 550 ° C, osmium has a high temperature Catalytic activity Unfortunately osmium is too scarce. Uranium was later shown to be equally highly catalytic. Basically, the problem has been solved. With the new device, uranium as the catalyst, at 550 ° C, 150-200 atmospheres of pressure, the ammonia concentration is already very high. in Working pressure Under moderate cooling, ammonia is liquefied and separated, while Gas mixture By converter, compressor and Circulating pump the Closed system Recycle, while constantly input the right amount of fresh gas mixture, and finally install one Heat exchanger The unit is literally a small factory, producing hundreds of milliliters of liquid ammonia per hour, with very low energy consumption. The prospects for industrial ammonia synthesis seem bright. However, laboratory methods are rarely used directly Industrial production The experimental device must be improved.

Synthetic ammonia is Haber The greatest achievement of his life, however, and it was not immediately favored by the industry, he was rewarded with cold eyes and suspicion. Although BASF is right Nitrogen fixation He was very interested in Haber's research on the electrooxidation of nitrogen, but expressed doubts about the prospects of Haber's ammonia synthesis. It was after a strong recommendation from Haber's friend and colleague, BASF consultant Car Engler, that BASF's technical leaders began to pay attention to Haber's work. One day in July 1909, Dr. C. Bosh, an engineer from BASF, and Dr. A. Mittasch, A chemist, came to Karlsruhe to see a demonstration of ammonia synthesis. Mita had seen the liquid ammonia flowing with her own eyes and trusted Hubble completely Value of law . Back in Ludwigshafen, they immediately set to work Haber The results were put into large-scale industrial trials. Three years later, an ammonia plant was built Put into operation . The credit for the large-scale industrialization of synthetic ammonia has always belonged to Bosch. Although the Karlsruhe laboratory has taken the most important step towards the industrial production of ammonia, there are still many difficult problems to achieve industrialization. Under Bosch's leadership, the successful resolution of these difficult problems is undoubtedly Chemical engineering The most outstanding achievement in the field. Haber won the 1918 year in 1919 Nobel Prize in Chemistry In 1931, Bosch and F. Bergius received the same honor. In his acceptance speech, Haber humbly said: "People have not fully realized that the Karlsruhe laboratory has not actually done anything Synthetic ammonia process Has made any contribution to industrialization." In recognizing the outstanding achievements made by Bosch and Burgess for the development of high-pressure methods in industry, the pioneers of high-pressure methods must not be forgotten Haber And Rossegur. As early as 1907, Haber's laboratory was known as a high pressure research center. After proposing the idea of hydrogenation of coal under high pressure, he made his first experiments in Karlsruhe in 1908.

In the first decade of the 20th century, studies on nitrogen oxidation under electric arc and Industrial application Have achieved rapid development. Haber's laboratory has been an important research center in this field. in Nernst 1904 pair Nitric oxide Thermal balance After the measurement, the pure thermal theory of arc nitrogen fixation was generally accepted, but it soon aroused many doubts. In one experiment, Haber found that the high yield did not agree with pure thermal theory, and that electrical factors played a role to some extent. Haber developed a great interest in this subject, in 1906-1910, on low temperature arcs Nitrogen fixation The problem has been studied in depth and detail. On account of actant The content of nitric oxide in the electrical equilibrium state exceeds the content of thermal equilibrium at the same temperature. When the electric field is removed, the excess nitric oxide will decompose until thermal equilibrium is fully established. Since the speed of this process decreases rapidly with decreasing temperature, at sufficiently low arc temperatures, almost nothing occurs decomposition Under these conditions, Nitric oxide The yield reached Maximum value . In reaching the final Thermal balance When high temperature arc inevitably leads to low yield. Haber proved the theory completely. The establishment of electrical equilibrium has also been proved. Let the air pass slowly through the 6cm length Alternating current arc , at 100mm mercury Under pressure, in a long, cold Quartz tube In medium combustion, the yield of nitric oxide obtained in this way is much higher than that at 2000℃ arc. The higher the arc temperature, the more oxides are produced, and the more beneficial the decomposition effect is. In general, Haber's work has tremendous theoretical and Technical value .

Flame and combustion

Haber's interest in flame and combustion problems was closely related to early research into fuel technology. The Thermodynamics of Industrial Gas Reactions, published in 1905, deals with the study of gas reactions in flames. The initial experiment was to study the water-vapor equilibrium using the homogeneous gas phase of a hydrocarbon flame. Smithells had invented fire separator And analyzed the flame Inner cone Main of Combustion product . Twenty years ago Le Chatry ( Le Chatelier First calculation Carbon dioxide The dissociation constant is derived from the composition of the flame gas Flame temperature . In 1865 Deville was obtained through a cold tube Carbon monoxide Inner flame The temperature of... Haber uses a new type of Deveri tube with high cooling efficiency to capture the gas in the intercone area of the flame. He proved that when Gas mixture When the inner cone is passed at a temperature of no less than 1250 ° C, the equilibrium is established virtually instantaneously. Hubble basis Equilibrium constant And the relationship between temperature is derived for an improved wide application Free energy Equation. In this way, the gas at any point of the flame is extracted and analyzed, and the temperature at that point can be obtained. Use this chemical flame thermometer Haber respectively determined the hydrocarbon flame, carbon monoxide flame, hydrogen flame and acetylene The temperature of the flame was very much in agreement with data obtained later by other researchers using different methods. Haber also studied the effects of nitrogen in flames oxidation . The process of gas explosion is well known Central Council of China generate Nitrogen oxide But little attention has been paid to this process in flames. Haber found that in a carbon monoxide flame, at one atmosphere of pressure, Nitrogen fixation Hardly happened, but at 10 atmospheres of pressure, Nitrogen oxide The yield is greatly increased. Under similar conditions, the nitrogen oxide yield in a hydrogen flame is only half that of a carbon monoxide flame. Haber studied the properties of the inner cone of a flame. It is estimated that the inner cone wall is only 0.1 mm thick. Hubble proved that it was the coldest part of the flame, not the hottest as previously thought. At the same time, the reaction rate in this region is particularly fast, chemiluminescence Strong and Degree of ionization High. Haber believes that these three are closely related to each other.

In 1906, Haber was promoted to professor at the Technical University of Karlsruhe. In 1911, he was invited to become the first director of the new Kaiser Wilhelm Institute for Physical Chemistry-Electrochemistry in Daholm, near Berlin. The institute was officially inaugurated in 1912. At the inauguration ceremony attended by the Kaiser, Haber demonstrated his invention of the gas whistle, a device capable of detecting dangerous gases in coal mines methane It is durable and works well, but has not been put into use. Haber The initial work at Daholm was to refine the study of synthetic ammonia, to determine the equilibrium of ammonia as accurately as possible and to obtain the final thermodynamic data Free energy The equation. Meanwhile, Harper began to pay attention Planck's quantum theory He was the first to recognize the significance of Planck's theory in chemistry. This became the basis of much of his work in Dahoum. Haber was particularly interested in the application of new physics knowledge to chemistry. His frequent discussions with his friend M. Born were of great help to his academic thinking. Born had just proposed a theory of ionic lattices: ionic Lattice energy By the distance between the ions Applied force Determined, solid reaction Heat of reaction Is equal to the algebraic sum of the lattice energies of its components. Born believed that the lattice could remove an electron from a gaseous atom to form a gaseous ion of energy and ion formation crystal The sum of energy. Haber clearly illustrated this energy relationship, hence the name Born - Haber Cycle, that is, lattice energy U is Heat of formation Q, dissociation energy D, Sublimation heat S, anion Ionization energy Algebraic sum of I and cation ionization energy E. Haber also boldly applied Born's theory to the HCl gas and obtained the reaction heat ratio of H++Cl-=HCl Cyclic process The calculated value is much smaller. To explain this deviation, in 1919 he proposed the idea of ionic deformation, an idea that would later bear fruit with Fajens. ^[3]

Leaf through Nobel Prize in Chemistry You can see that there were no awards in 1916-1917, because during this period, Europe was experiencing World War I In 1918, the prize for Chemistry was awarded to German chemists Haber . This set off a debate among scientists, with some in Britain, France and other countries openly objecting, arguing that Hubble did not deserve the honor. Why is this?

With the development of agriculture, the nitrogen fertilizer Quantity demanded Is growing rapidly. Before the 19th century, the main source of nitrogen fertilizer for agriculture came from Organic matter Byproducts such as manure, seed cakes and Green manure . In 1809 Chile Found a big one Sodium nitrate It was mined very quickly. On the one hand, due to the limited availability of this mineral deposit, on the other hand, the military industry also needs a large amount of explosives Saltpeter Therefore, to solve the source of nitrogen fertilizer must find another way.

Some visionary chemists have pointed out that in order to save future generations from hunger, considering the food problems of the future, we must hope that scientists can realize the atmosphere Nitrogen fixation . Therefore, the fixation and conversion of the abundant nitrogen in the air into a usable form became a major topic that attracted the attention and concern of many scientists in the early 20th century. Haber Be engaged in Synthetic ammonia One of the chemists of experimental and theoretical study of process conditions.

The industrial production of ammonia synthesis using nitrogen and hydrogen as raw materials was a difficult subject, and it took about 150 years from the first laboratory development to industrial production. In 1795 an attempt was made to synthesize ammonia at normal pressure, and later another at 50 large Atmospheric pressure I tried them all, and they all failed. In the second half of the 19th century, Physical chemistry It was realized that the synthesis of ammonia from nitrogen and hydrogen was reversible, and that increasing the pressure would push the reaction in the direction of ammonia formation: increasing the temperature would move the reaction in the opposite direction, whereas too low a temperature would make the reaction more reversible Reaction rate Too small; The catalyst will have an important effect on the reaction. This actually provides theoretical guidance for the experiment of synthetic ammonia. At that time, the authority of physical chemistry, Germany's Nernst clearly pointed out that nitrogen and hydrogen are able to synthesize ammonia under high pressure conditions, and provided some Experimental data . The French chemist Le Chatry was the first to attempt a high-pressure ammonia synthesis experiment, but he abandoned the dangerous experiment because oxygen was mixed into the nitrogen and hydrogen mixture gas, causing an explosion. Have a good foundation in the field of physical chemistry research Haber Determined to overcome this daunting problem.

Haber first conducted a series of experiments to explore the optimal physicochemical conditions for the synthesis of ammonia. Some of the data he obtained in the experiment were different from Nernst's, and he did not blindly follow the authority, but relied on the experiment to check and finally confirmed Nernst The calculation is wrong. With the help of a student from the United Kingdom, Rossenor, Haber succeeded in devising a system suitable for High pressure experiment The device and synthesis of ammonia Process flow The process is: blowing in over hot coke Water vapor You can get almost equal volume Carbon monoxide A mixture of gas and hydrogen. The carbon monoxide is further reacted with water vapor under the action of catalyst to obtain Carbon dioxide And hydrogen. Then the mixed gas is dissolved in water at a certain pressure, the carbon dioxide is absorbed, and the purer hydrogen is produced. Water vapor is also mixed with the right amount of air through Red heat Carbon, oxygen and carbon in the air form carbon monoxide and carbon dioxide, which are absorbed and removed, thus obtaining the required nitrogen.

Ammonia is synthesized by the mixture of nitrogen and hydrogen under the condition of high temperature and pressure and under the action of catalyst. But what kind of high temperature and high pressure conditions are optimal? What kind of catalyst is the best? This also requires a great deal of exploration. With perseverance, through constant experimentation and calculation, Haber The encouraging results were finally achieved in 1909. This is that under the conditions of high temperature of 600℃, 200 atmospheres and osmium as catalyst, synthetic ammonia with a yield of about 8% can be obtained. 8% Conversion rate It's not high. Of course it will affect production Economic benefit . Haber knew that the synthetic ammonia reaction could not achieve as high a conversion rate as in the production of sulfuric acid Sulfur dioxide Oxidation reaction The conversion rate is almost 100%. What to do? Haber believes that if the reaction gas can be cycled under high pressure, and the ammonia generated by the reaction can be separated from this cycle Technological process It's doable. So he successfully designed the recycling process of raw gas. This is the Haber process for making ammonia.

Getting out of the lab and into industrial production still requires hard work. Haber patented his process and gave it to Baden, the largest chemical company in Germany at the time aniline and Soda ash manufacturing The company. The company originally planned to use the electric arc method of production Nitrogen oxide And then synthesize ammonia Production method . In contrast, the company immediately canceled the original plan and organized a team led by chemical expert Bosch Engineering technician will Haber The design was put into practice.

First, according to the Haber process, they found a more reasonable way to produce a large amount of cheap raw materials nitrogen and hydrogen. Through experiments, they realized that osmium is a very good catalyst, but it is difficult to process because it is easily transformed into a liquid when it comes into contact with air volatility the tetroxide Another one Rare metal There are very few reserves in the world. The second catalyst Haber suggested was uranium. Uranium is not only expensive, it's good trace Both oxygen and water are sensitive. In order to find an efficient and stable catalyst, they conducted as many as 6,500 experiments over two years, testing 2,500 different formulations, and finally settled on lead-containing magnesium accelerator the Iron catalyst . The development of suitable high-pressure equipment is also the key to the process. It was able to withstand 200 atmospheres Mild steel But fear of hydrogen decarbonization corrosion. Bosch thought through a number of options, and finally decided to add a wrought iron lining to the mild steel reaction tube, Wrought iron Although it has no strength, it is not afraid of hydrogen corrosion, so it finally solved the problem.

Haber The idea of synthetic ammonia was finally realized in 1913, when an ammonia plant with a daily capacity of 30 tons was built and put into operation. Since then, ammonia synthesis has become Chemical industry A rapidly developing and very active part of China. The creation of synthetic ammonia production methods not only opened up access Fixed nitrogen The way, and more importantly this one Production technology The implementation of the whole Chemical technology The development has had a significant impact. The research of synthetic ammonia comes from the correct theoretical guidance, in turn, the research and test of synthetic ammonia production technology has promoted Scientific theory The development of... In view of Synthetic ammonia industry The realization of production and the promotion of its research to the development of chemical theory, decided to put Nobel Prize in Chemistry It was right to award Harper. Harbour's acceptance of the award is well deserved.

Some British and French scientists argued that Hubble did not deserve it Nobel Prize Why? Some people have thought that if not Synthetic ammonia industry Germany did not have enough ammunition reserves, and the military did not dare to launch it rashly World War I . With the ammonia industry, you can turn Ammonia oxidation for nitrate To ensure the production of gunpowder, otherwise only rely on Chile Saltpeter Gunpowder is no guarantee. Of course some science Invention and creation Being used in unjust wars, scientists are not Direct liability Yes. Criticism of Hubble in the British and French scientific communities focused more on Hubble's performance in World War I.

In 1906, Haber became University of Karlsruhe He was appointed professor of chemistry in 1911 Berlin The suburb of William physical chemistry and electrochemistry Director of the institute, concurrently University of Berlin Professor. The year 1914 World war Outbreak, nation chauvinism Fanned by blind patriotic fervor, Harper was deeply involved in the whirlpool of war. The laboratory he led became an important military institution for the war effort: Haber was responsible for the supply and development of materials needed for the war effort, especially in the development of war gases. He had mistakenly believed that the gas attack was a good way to end the war and shorten the war, and thus became the war Deutschland Central The scientific head of the gas war.

On Haber's advice, the German army loaded it in January 1915 chlorine The cylinders were placed at the front of the position and used the wind to blow chlorine gas towards the enemy line. The first time Field test Get ahead. It was launched by the German Army on 22 April of that year The Battle of Ypres In the 6 km wide Forward position In five minutes, the Germans released 180 tons of chlorine gas, a yellow-green gas about a man high, along the ground in the wind towards the British and French positions (chlorine gas is heavier than air, so it sinks in the lower layers and moves along the ground), into the trenches and stays there. The wave caused British and French troops to experience nasal and throat pains, and some of them suffocated to death. So the English and French soldiers were frightened into a panic and ran in all directions. It is estimated that about 15,000 British and French troops were poisoned. This is Military history On the first use of mass destruction Toxic agent The beginning of modern chemical warfare. Since then, both warring sides have used poison gas, and new types of poison gas have been developed. The casualties caused by the gas were not even estimated by the German authorities. However, the use of gas, carried out Chemical warfare It was unanimously agreed upon by the peoples of Europe denounce . Scientists are even more critical of this inhuman practice. In view of this, British, French and other scientists are rightly opposed to the award Haber Nobel Prize in Chemistry . Harper was so emotionally shaken by this, End of war Soon, he fled to the countryside for about six months, fearing he would be considered a war criminal.

It's Harber

Invented the catalyst

To make use of the infinite nitrogen in the air:

He uses... Scrap iron Fixed nitrogen,

Make tons of ammonia and various fertilizers

Pouring out of German factories.

Just a few months later,

Lead to Chile The shipping lanes were cut off,

Chilean saltpeter and guano The source of the severance;

And at that time,

World War I Overcast,

Germany needs to stock up on arms.

It's Harber

Master the function of catalyst:

Catalysts in chemical reactions

Rather than stand idly by,

It's involved in

Or whittle away the mountains that block the reaction,

Thus reducing the reaction Critical point ,

Or dig a tunnel,

Or the arm of the molecule

Pull in the hardest to react to,

To bond or Broken bond

It was easy. I got what I wanted.

The regenerated catalyst

I'm back on my feet. I'm still a matchmaker.

It's Harber

Dressed up a handful of iron filings,

Let it produce millions of tons of nitrogen.

The principal advisor to the Kaiser Wilhelm Institute,

As a catalyst to end the war;

his Chemical weapons Bringing victory to the trenches,

dumdum , shrapnel ,

Be no match for burn With lung collapse soup

In Ypres

When the soldier unscrewed the chlorine canister

Let the green gas spread over the fields of dawn,

He was taking careful notes,

Forget all the sad letters from my wife.

It's Harber

In post-war Berlin,

Wallow in Hydragenum And in sulfur,

Golden elixir The whole warlock thing

To change both the world and themselves;

Harper's whimsical --

Extracting millions of gold atoms per liter of water,

Turn the sea full Gold bar The warehouse of

To pay off Germany's war debt.

And in this world, things are changing,

Oh, in Munich People have heard

Nazi advancing Leather boots {* SOB sniff *}

People swallow their grudges to fill their stomachs.

This Haber

Another catalyst to find

It was himself:

In an exotic town on the Rhine Basel ,

He catalyzed himself

erstwhile Protestant Haber, the council adviser

And now the humble Jew Harper,

In the cunning Jindan Warlock

The * city of Paracelsus,

He came to the end of his life.

Fritz Haber

catalogue

Character introduction

Life experience

Obsessed with the chemical industry

Establishment of academic center

Academic achievement

Nobel Prize in Chemistry

supporter

objector

The Harper Song