Fritz Haber: German Chemist Who Discovered the Synthesis of Ammonia

Fritz Haber was born on December 9, 1868, in Breslau, Germany, into one of the town's oldest families, as the son of trader Siegfried Haber and Paula Haber. Fritz attended the St. Elizabeth classical school in Breslau and conducted numerous chemical experiments there. From 1886 to 1891, he studied chemistry under Bunsen at the University of Heidelberg, A.W. Hoffmann at the University of Berlin, and Liebermann at the Technical School in Charlottenburg. After finishing university, Haber volunteered at his father's chemical business. Because he was interested in chemical technology, he also worked under Professor Georg Lunge at the Zurich Institute of Technology.

He subsequently opted to pursue a scientific career and spent one and a half years working with Ludwig Knorr at Jena, writing a joint paper with him. Being unsure whether to pursue chemistry or physics, he was given and accepted an assistantship at Karlsruhe by Hans Bunte, a Professor of Chemical Technology at the time. He stayed there until 1911. Bunte was particularly interested in combustion chemistry, and Carl Engler, who was also present, introduced Haber to the study of petroleum; both of these colleagues significantly influenced Haber's subsequent work.

Haber received his Privatdozent degree in 1896 for his thesis on experimental hydrocarbon decomposition and combustion studies. In 1906 he was named Professor of Physical Chemistry and Electrochemistry and Head of the Institute created in Karlsruhe to investigate these subjects. Then, in 1911, he was nominated to succeed Engler as Director of the Institute for Physical and Electrochemistry in Berlin-Dahlem. He remained there until 1933 when the Nazi race laws forced practically all his employees to quit. Sir William Pope invited him to Cambridge, England, where he stayed for a while. Haber had been suffering from heart disease for some time and, fearing the English winter, had relocated to Switzerland.

Haber's textbook on electrochemistry, based on his lectures at Karlsruhe, was published in 1898. In the preface to his book, he stated his intention to relate chemical research to industrial processes. The following year, he published his work on electrolytic oxidation and reduction, demonstrating that definite reduction products can result if the potential at the cathode is kept constant. In 1898, he described the reduction of nitrobenzene at the cathode in steps, which provided the model for numerous similar reduction processes.

His work on the electrolysis of solid salts, on the establishment of the quinone-hydroquinone equilibrium at the cathode, laid the foundations for Biilmann's quinhydrone electrode for determining the acidity of a liquid; however, Haber invented the glass electrode for the same purposes, which is now widely used, in collaboration with Cremer. This prompted Haber to conduct the first experimental studies of the possible differences that exist between solid electrolytes and their aqueous solutions, which piqued the curiosity of physiologists.

Around this time, Haber also investigated the energy loss caused by steam engines, turbines, and motors powered by fuel and sought methods of minimising this loss using electrochemical means. He did not find a commercially relevant answer to this challenge but discovered a basic solution for the laboratory combustion of carbon monoxide and hydrogen.

He subsequently switched to flame research, doing important studies on the Bunsen flame, demonstrating that a thermodynamic water-gas equilibrium is created in the light inner cone of this flame and that water-gas combustion occurs in its outer mantle. This resulted in the development of a chemical approach for estimating flame temperatures. Haber then began work on nitrogen fixation from the air, for which he was awarded the Nobel Prize in Chemistry in 1918.

He released his book on the thermodynamics of technical gas reactions in 1905, in which he recorded the creation of modest amounts of ammonia from N2 and H2 at 1000° C using iron as a catalyst. Subsequently, after searching for suitable catalysts, he attempted the synthesis of ammonia by passing nitrogen and hydrogen over the catalyst at a pressure of 150-200 atmospheres and a temperature of around 500° C. This resulted in the development of the Oppau and Leuna Ammonia Works, with the cooperation of Bosch and Mittasch, which enabled Germany to prolong the First World War when her supply of nitrates for explosives ran out in 1914.

Improvements to the Haber process also produced ammonium sulphate for use as a soil fertiliser. The idea used in this procedure, as well as the subsequent development of the control of catalytic reactions at high pressures and temperatures, led to Alwin Mittasch's synthesis of methyl alcohol, as well as the hydrogenation of coal using the Bergius method and the creation of nitric acid.

During the years between the two World Wars, Haber developed his firedamp whistle for miners' protection, his quartz thread manometer for low gas pressures, and his discovery that adsorption powers can be due to unsaturated valence forces of a solid body, which Langmuir founded his theory of adsorption on. When the First World War broke out, he was hired as a consultant to the German War Office, where he planned gas attacks and defences. This and other tasks harmed his health, and he was forced to work in administration for a period. He was a member of the League of Nations Committee on Chemical Warfare and the German Relief Organization.

From 1920 to 1926, he experimented with the recovery of gold from seawater to allow Germany to satisfy her war reparations. In addition, he devoted himself to the reorganisation of his Institute, to which he selected sectional directors with complete flexibility in their work after being greatly depressed by the failure of this project, which he attributed to his own lack. Among these were James Franck, Herbert Freundlich, Michael Polanyi, and Rudolf Ladenburg; substantial work on colloid chemistry and atomic physics came from the Institute.

During the period, Haber made significant efforts to re-establish Germany's scientific contacts with other countries, and the colloquia he hosted every two weeks contributed significantly to his Institute's international renown. During his final years, he worked on chain reactions, oxidation processes, and hydrogen peroxide catalysis.

Apart from the Nobel Prize, Haber got other honours throughout his life. Haber died on January 29, 1934, in Basle, on his way from England to Switzerland to recuperate, his spirit devastated by his rejection by the Germany he had served so brilliantly.