Haber, Fritz, ammonia synthesis

A second and greater opportunity came his way in the spring of 1922. Professor Fritz Haber, discoverer of the Haber ammonia synthesis process and head of the Kaiser Wilhelm Institute for Physical Chemistry (now known as the Max Planck Institute), contacted Professor Schlenk. 

To conclude, it is worth recording the advice given to the author at the very start of his career by the veteran catalytic chemist Alwin Mittasch, who had been Fritz Haber s officer in charge of catalyst research for the ammonia synthesis In all catalytic studies only the very purest is good enough . 

Reactions which may occur on sites consisting of one or two atoms only on the surface of the catalyst are generally known as facile reactions. Reactions involving hydrogenation on metals are an example. Eor such reactions, the state of dispersion or preparation methods do not greatly affect the specific activity of a catalyst. In contrast, reactions in which some crystal faces are much more active than others are called structure sensitive. An example is ammonia synthesis (discovered by Fritz Haber in 1909 (Moeller 1952)) over Fe catalysts where (111) Fe surface is found to be more active than others (Boudart 1981). Structure-sensitive reactions thus require sites with special crystal structure features, which... 

Around 1900 Fritz Haber began to investigate the ammonia equilibrium [11] at atmospheric pressure and found minimal ammonia concentrations at around 1000 °C (0.012 %). Apart from Haber, Ostwald and Nernst were also closely involved in the ammonia synthesis problem, but a series of mistakes and misunderstandings occurred during the research. For example, Ostwald withdrew a patent application for an iron ammonia synthesis catalyst because of an erroneous experiment, while Nernst concluded that commercial ammonia synthesis was not feasible in view of the low conversion he found when he first measured the equilibrium at 50 - 70 bar [12] - [14],... 

Ammonia has been produced commercially from its component elements since 1909, when Fritz Haber first demonstrated the viability of this process. Bosch, Mittasch and co-workers discovered an excellent promoted Fe catalyst in 1909 that was composed of iron with aluminium oxide, calcium oxide and potassium oxide as promoters. Surprisingly, modem ammonia synthesis catalysts are nearly identical to that first promoted iron catalyst. The reaction is somewhat exothermic and is favoured at high pressures and low temperatures, although, to keep reaction rates high, moderate temperatures are generally used. Typical industrial reaction conditions for ammonia synthesis are 650-750 K and 150-300 atm. Given the technological importance of the... 

In 1909 the German Chemist Fritz Haber discovered a catalyzed process [13], which allowed the synthesis of ammonia (NH3) from the elements hydrogen and nitrogen. He received the Nobel prize in chemistry for his discovery. The Nobel prize for Fritz Haber was a subject of controversy because Haber is also the inventor of war gas (phosgene COCI2), which killed hundreds of thousands of soldiers in World War I. Conscience-stricken, Haber s wife committed suicide. Carl Bosch succeeded to scale up Haber s synthesis from the laboratory scale to industrial production. After World War I other industrialized countries also introduced ammonia synthesis and therefore the consumption of hydrogen increased rapidly. 

BASF high pressure converter for ammonia synthesis, with (inset) Carl Bosch (above) and Fritz Haber (below). Photos courtesy BASF (converter and Haber), and Deutsches Museum, Munich (Bosch). Reproduced from the cover of Chemistry Industry, 2 August 1993, with permission. 

Fritz Haber for the synthesis of ammonia from its elements. 

Although Fritz Haber was a fine scientist and the success of his ammonia synthesis made him a rich man, he ultimately had a tragic life. At the start of World War 1 he joined the German Ghemical Warfare Service, where he supervised the use of chlorine as a chemical weapon during the battle of Ypres in France. This first use of a chemical weapon led to further tragic developments in chemical warfare and also to personal tragedy for Haber. His wife... 

Haber, Fritz (1868-1934) German chemist who, with brother-in-law Carl Bosch, invented a process for the synthesis of ammonia from hydrogen and atmospheric nitrogen, thus overcoming the shortage of natural nitrate deposits accessible to the German explosives industry in World War I. Haber s development of the process on an industrial scale provided copious quantities of fertilizers and also prompted the development of the chemical industry and chemical engineering. For his work, Haber received the Nobel Prize in chemistry in 1918. 

Figure 6.1.1 Schematic presentation oflaborat07 apparatus of Fritz Haber and his assistant Robert Le Rossignol for ammonia synthesis the original can be seen in the German museum (Deutsches Museum), Munich, Germany A catalytic oxidation of traces of oxygen by hydrogen present in the feed gas by a platinum catalyst B separation of steam formed in A C water cooled laborato -scale NH3 reactor D cooled vessel for separation of NH3.

The two main developments in science that initiated industrial catalysis were the discoveries of catalytic hydrogenation by Paul Sabatier and the ammonia synthesis by Fritz Haber, which built upon the chemical equilibrium thermodynamics of Jacobus van t Hoff and the rate equation of Svante Arrhenius. Many processes, often based on catalytic hydrogenation, followed. Section 1.2 gives a historic review of the early developments in catalysis. Because of its pivotal role in the initiation of industrial catalysis, we devote an entire section to the development of the ammonia synthesis. 

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