Confined NiRu Bimetallic Catalysts for the Hydrogenation of Dimethyl Terephthalate to Dimethyl Cyclohexane-1,4-dicarboxylate

Abstract

The structure of the catalyst plays an important regulatory role in heterogeneous catalysis. Herein, we report the preparation of a novel NiRu bimetallic catalyst Ru/Ni/Ni(Al)Ox, confined by a weak crystalline Ni(Al)Ox matrix, by the reduction of an NiAlRu-layered double hydroxide (LDH) precursor in hydrogen atmosphere. Doping Ru3+ in LDH can facilitate the reduction of Ni2+ by hydrogen spillover and obviously decrease the size of Ni particles. The catalytic performance was evaluated by dimethyl terephthalate (DMT) hydrogenation to dimethyl cyclohexane-1,4-dicarboxylate (DMCD). The Ru/Ni/Ni(Al)Ox sample showed an enhanced catalytic activity with the conversion rate of DMT 99.3% and the selectivity of DMCD 93.2%. The reduction temperature can greatly affect the microstructure evolution and accordingly the catalytic performance. The synergistic effect of metal Ru and Ni is proposed to enhance the ability to activate H2 and to adsorb DMT on the Ni(Al)Ox matrix.