Which process does not involve a catalyst?

For example, in Haber’s process for manufacture of ammonia, molybdenum acts as a promoter for iron which is used as a catalyst.

${\mathrm{N}}_2+3{\mathrm{H}}_2\underset{2. \mathrm{Mo} \left(\mathrm{s}\right)}{\overset{1. \mathrm{Fe}\left(\mathrm{s}\right)}{\to }}2{\mathrm{NH}}_3$

Oxidation of ammonia into nitric oxide in the presence of platinum gauze in Ostwald’s process.

$4{\mathrm{NH}}_3+5{\mathrm{O}}_2\stackrel{\mathrm{Pt} \left(\mathrm{s}\right)}{\to }4\mathrm{NO}+6{\mathrm{H}}_2\mathrm{O}$

Manufacture of ammonia using iron as a catalyst, manufacture of H₂SO₄ by contact process and use of finely divided nickel in the hydrogenation of oils are excellent examples of heterogeneous catalysis.

Mixture of aluminum (Al) powder and ferric oxide (Fe₂O₃) is known as thermite process (no catalyst is required).

$4\mathrm{Al}+2{\mathrm{Cr}}_2{\mathrm{O}}_3\to 2{\mathrm{Al}}_2{\mathrm{O}}_3+4\mathrm{Cr}$

Therefore, option B is correct.