The role of carburization temperature on the molybdenum carbide surface and their catalytic activity

Abstract

The surfaces of molybdenum carbide were varied by changing the carburization temperature between 823 and 1123 K. The surfaces of the catalytic material were investigated using <em>in-situ</em> temperature program carburization followed by temperature program reduction and oxidation. <em>In-situ</em> temperature program oxidation (TPO) showed the surfaces of the catalysts contain a similar amount of carbonaceous deposit, while temperature program reduction (TPR) showed their ability to consume hydrogen in different amounts. The result shows the surface of the carbide at 823 K contained oxygen, while those carburized at higher temperature (≥ 923 K) were pure carbide. The catalysts tested for hydroisomerization of n-heptane and the catalyst with oxycarbide surface showed higher activity and iso-heptane selectivity. Hence, carburization temperature plays a crucial role in the formation of an active catalyst.