Synthesis, characterization and catalytic activity in the hydrogenation of cyclohexene with molybdenum carbide

Abstract

Two series of molybdenum carbides are prepared from MoO3 by temperature programmed reduction (TPR), differing in feed gas composition (20 and 40% CH4/H-2). The heating ramp consists of two steps, one from ambient temperature to 973 K, at a rate of 10 K/min

the second from 973 K up to the final temperature (1023, 1073, 1123, 1173 K), at a rate of 0.5 K/min. The Mo2C (hcp) phase is identified for the series prepared with 20% CH4/H-2 at different temperatures, with surface areas between 20 and 27 m(2)/g. Also found is a mix of the MoC and Mo2C (hcp) phases for the series prepared with 40% CH4/H-2 at temperatures above 1023 K, with surface areas between 9 and 19 m(2)/g. Both series of catalysts reach 100% conversion of cyclohexene in 5 h or less, with those catalysts prepared with a 40% CH4/H-2 gas mix reaching maximum conversion in the least time. Catalysts are compared to a commercial molybdenum carbide reagent as a reference.