How is ammonia manufactures industrially?

Ammonia is manufactured industrially by Haber's process from nitrogen and hydrogen.

$N_2\left(g\right)+3H_2\left(g\right)\stackrel{\begin{array}{c}F{e}_2{O}_3/K_{2}OandA{l}_2{O}_3\\ 700K,200atm\end{array}}{\rightleftharpoons }\underset{{\Delta }_f{H}^o=-46.1kJmo{l}^{-1}}{2N{H}_3\left(g\right)}$

According to Le-Chatelier's principle, high pressure would favour the production of ammonia. Optimum conditions for production of $N{H}_3$ are

1. Temperature ~700 K

2. Pressure -$200\times {10}^5$ Pa (or 200 atm)

3. Catalyst- $F{e}_2{O}_3$

4. Promotor - $K_{2}OandA{l}_2{O}_3$

Note Earlier Fe was used as catalyst with molybdenum.