Question

Which of the following acts as a catalyst in Haber’s process

• A. Finely divided iron with molybdenum as a promoter
• B. Finely divided Nickel and soda lime deposited over pumice stone
• C. Finely divided Osmium or Uranium
• D. All of the above

Answer 1

The correct option is D All of the above

Once the pure reagents of dinitrogen and dihydrogen gas are obtained, the following simple reaction can give ammonia:
$N_2\left(g\right)+3H_2\left(g\right)\rightleftharpoons 2N{H}_3\left(g\right)$
According to Le Chatelier’s principle, to favour the forward reaction, high pressures and lower temperatures are required. But the use high pressures, escalates the construction costs of the plant. Also, at lower temperature, although the yield of ammonia is more yet the reaction is very slow kinetically. In order to speed up the reaction, catalysts are used. Options A B & C are all well-known catalysts which are/were used in ammonia plants. Promoter (Molybdenum) is any component added to a catalyst to increase activity or selectivity.
While using catalysts, there is a trade-off between the kinetics and the equilibrium of the reaction. With modern high-performance catalysts, the optimum conditions are ${400}^{\circ }C$ - ${500}^{\circ }C$. One of the most significant catalysts is finely divided iron containing traces of potassium, aluminum, calcium, magnesium, silicon, and oxygen.