MgAl-LDO mixed oxide derived from layered double hydroxide: A potential support for CoMo sulfur-resistant water–gas shift catalyst

Abstract

A series of Mg–Al layered double oxides (MgAl-LDOs) with different Mg/Al molar ratios (Mg/Al=3–6) was synthesized by calcination of Mg–Al layered double hydroxides, and further used to prepare CoMo water–gas shift (WGS) catalysts by incipient-wetness impregnation method. The as-synthesized CoMo/MgAl-LDO catalysts were investigated by systematically physicochemical characterizations. The CoMo/MgAl-LDO (Mg/Al=5) catalyst showed much higher catalytic activity than a commercial CoMo/MgAl2O4 catalyst, indicating the MgAl-LDOs can be a potential support for the CoMo catalyst. H2-TPR and H2S-TPS studies suggest that the Mo species are easier to be reduced and thus more sulfide phases are formed on CoMo/MgAl-LDO (Mg/Al=5) catalyst.