Deactivation and testing of molybdenum nitride catalysts in hydrodesulfurization of dibenzothiophene

Abstract

The deactivation kinetics of the 97.1% MoO 3 /Al 2 O 3 treated in NH 3 and sulfided in 10% H 2 S/H 2 at various temperatures for the hydrodesulfurization (HDS) of dibenzothiophene was studied based on regression analysis. The sulfur accumulated on the surface during the reaction led to forming molybdenum sulfide, poisoning active sites, and decreasing the catalyst activity. The activities of the NH 3 -treated catalysts remarkably decreased up to 2 h (the initial stage) but gradualy decreased at the steady state of the reaction, compared to the sulfided catalysts. The catalyst life of the 973 K-treated catalyst was 1.4 times longer than that of the 773 K and 5 times longer than that of 1173 K-treated catalysts. The catalyst life for the nitrided catalysts was longer than that of the sulfided catalysts. The NH 3 -treated catalyst is a good catalyst of long-time-duration for dibenzothiophene HDS.