Haber process
The Haber process, also called the Haber–Bosch process, is the main industrial procedure for the production of ammonia. It converts atmospheric nitrogen (N2) to ammonia (NH3) by a reaction with hydrogen (H2) using finely divided iron metal as a catalyst:
![{\displaystyle {\mathrm {N} {\vphantom {A}}_{\smash[{t}]{2}}{}+{}3\,\mathrm {H} {\vphantom {A}}_{\smash[{t}]{2}}{}\mathrel {\longrightleftharpoons } {}2\,\mathrm {NH} {\vphantom {A}}_{\smash[{t}]{3}}}\qquad {\Delta H_{\mathrm {298~K} }^{\circ }=-92.28~{\text{kJ per mole of }}{\mathrm {N} {\vphantom {A}}_{\smash[{t}]{2}}}}}](./_assets_/eb734a37dd21ce173a46342d1cc64c92/ba3d04f7488f3eb39ea50f0c05bccf43243ae4fe.svg)
This reaction is exothermic but disfavored in terms of entropy because four equivalents of reactant gases are converted into two equivalents of product gas. However, due to the extremely high kinetic barriers to bond cleavage, high pressures and temperatures are needed to drive the reaction forward. The Haber Process was first created by the German Chemist Fritz Haber, then developed after a few years by Carl Bosch.
The German chemists Fritz Haber and Carl Bosch developed the process in the first decade of the 20th century, and its improved efficiency over existing methods such as the Birkeland–Eyde and Frank–Caro processes was a major advancement in the industrial production of ammonia.
The Haber process can be combined with steam reforming to produce ammonia with just three chemical inputs: water, natural gas, and atmospheric nitrogen. Both Haber and Bosch were eventually awarded the Nobel Prize in Chemistry: Haber in 1918 for ammonia synthesis specifically, and Bosch in 1931 for related contributions to high-pressure chemistry.