Highly carbon-resistant Ni-Co/SiO2 catalysts derived from phyllosilicates for dry reforming of methane

This paper describes synthesis and characterization of Ni and Ni-Co alloy supported over SiO2 derived from phyllosilicates. A series of 10 wt% Ni- Co phyllosilicate supported over SiO2 with different Ni/Co ratio is successfully prepared by hydrothermal method where urea is used to release ammonia gradually providing a basic environment. TPR results show that adding of Co enhances the metal-support interaction. After H-2 reduction at high temperature, small and uniform Ni- Co alloy particles are well supported over silica. These catalysts are tested for dry reforming of methane (DRM) at 750 degrees C. The catalytic performance is highly affected by Ni/Co ratio: 10Ni and 7Ni3Co show high and stable activity for 100 h, whereas 5Ni5Co, 3Ni7Co and 10Co exhibit severe deactivation due to oxidation of metal sites. A harsher test has shown that adding of Co with a proper amount indeed can help to suppress metal sintering and carbon formation. (C) 2017 Elsevier Ltd. All rights reserved.