The following step is one of the key steps involved in the preparation of hydrogen.

$\mathrm{CO}\left(\mathrm{g}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right) \stackrel{\mathrm{X}/673\mathrm{K}}{\to } {\mathrm{CO}}_2\left(\mathrm{g}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right) ;$The catalyst ‘X’ in the reaction is

First step of the process is coal gasification;

$\mathrm{C}\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)\stackrel{1273 \mathrm{K}}{\to }\mathrm{CO}\left(\mathrm{g}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right) ;$

 Second step of the reaction is called water gas shift reaction, the catalyst used is iron chromate ;

$\mathrm{CO}\left(\mathrm{g}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)\underset{673 \mathrm{K}}{\overset{\mathrm{Iron} \mathrm{chromate}}{\to }}{\mathrm{CO}}_2\left(\mathrm{g}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right) ;$