Haber process

The Haber process, also called the Haber–Bosch process, is the main industrial procedure for the <a href="/facts/Ammonia_production/XECy4A88">production of ammonia</a>. It converts atmospheric <a href="/facts/Nitrogen/Nf1QpGDz">nitrogen</a> (N2) to <a href="/facts/Ammonia/MtLtJFtz">ammonia</a> (NH3) by a reaction with <a href="/facts/Hydrogen/BoYHjl0J">hydrogen</a> (H2) using finely divided <a href="/facts/Iron/QK1JYy8E">iron</a> metal as a catalyst:

 
 
 
 
 
 N
 
 2
 
 
 
 
 
 +
 3
 
 
 H
 
 2
 
 
 
 
 
 
 
 
 
 
 
 ↽
 
 
 
 
 −
 
 
 
 
 
 
 
 
 −
 
 
 
 
 ⇀
 
 
 
 
 
 
 2
 
 
 NH
 
 3
 
 
 
 
 
 
 
 
 Δ
 
 H
 
 
 298
  
 K
 
 
 
 ∘
 
 
 =
 −
 92.28
  
 
 kJ
 
 /
 
 mol
 
 
 
 
 {\displaystyle {\ce {N2 + 3H2 <=> 2NH3}}\qquad {\Delta H_{\mathrm {298~K} }^{\circ }=-92.28~{\ce {kJ/mol}}}}

This reaction is thermodynamically favorable at a high temperature, but the kinetics are prohibitively slow. At high temperatures at which catalysts are active enough that the reaction proceeds to equilibrium, the reaction is reactant-favored rather than product-favored. As a result, high pressures are needed to <a href="/facts/Le_Chatelier%27s_principle/sHkpGM0r">drive the reaction forward</a>. 
The German chemists <a href="/facts/Fritz_Haber/cj5QTJKT">Fritz Haber</a> and <a href="/facts/Carl_Bosch/3NwIre59">Carl Bosch</a> developed the process in the first decade of the 20th century, and its improved efficiency over existing methods such as the <a href="/facts/Birkeland%E2%80%93Eyde_process/KlYdcX0b">Birkeland-Eyde</a> and <a href="/facts/Frank%E2%80%93Caro_process/IGjLkykH">Frank-Caro</a> processes was a major advancement in the industrial production of ammonia. The Haber process can be combined with <a href="/facts/Steam_reforming/5lNIv6rr">steam reforming</a> to produce ammonia with just three chemical inputs: water, natural gas, and atmospheric nitrogen. Both Haber and Bosch were eventually awarded the <a href="/facts/List_of_Nobel_laureates_in_Chemistry/7osWRyAd">Nobel Prize in Chemistry</a>: Haber in 1918 for ammonia synthesis specifically, and Bosch in 1931 for related contributions to <a href="/facts/High-pressure_chemistry/EsTmp5TW">high-pressure chemistry</a>.

Haber process open-in-new

Haber process