Facilitated hydrogenation of furfural into furfuryl alcohol over catalyst CuSiAlOx made with infrared-heating calcination

Abstract

A CuSiAlO_x catalyst was prepared through infrared-heating calcination and employed to catalyze vapor furfural (FFR) hydrogenation in a fixed-bed reactor. Its catalytic performance was systematically evaluated and compared to that of a catalyst derived from the same precursor but calcined using an electric oven. The hydrogenation tests were performed at temperatures varying in 140 ∼ 180 °C, H₂/FFR (mol/mol) ratios in 4:1 ∼ 8:1, and liquid hourly space velocity (LHSVs) in 0.6 ∼ 1.0 h^-1. The catalyst CuSiAlO_x-IH (prepared by infrared-heating calcination) demonstrated higher FFR conversion than CuSiAlO_x-EH (prepared by electric-oven heating) did. Under the conditions of a H₂/FFR ratio of 6:1, a temperature of 140 °C, and an LHSV of 0.6 h^-1, the CuSiAlO_x-IH catalyst achieved a 99.70 % FFR conversion and 95.72 % selectivity to furfur alcohol (FOL) in a continuous test for 18 h. This time duration with good stability was twice longer than that enabled by CuSiAlO_x-EH. Characterization of the fresh, reduced, and spent catalysts revealed that the catalyst CuSiAlO_x-IH, compared to CuSiAlO_x-EH, possessed more Cu defects, a higher BET surface area, a smaller average size, and the narrower size distribution of active-species particles. These structural advantages thus rendered the CuSiAlO_x-IH catalyst superior in its catalysis of the FFR hydrogenation reactions.