Effect of Strong Metal Support Interactions of Supported Ni and Ni-Co Catalyst on Metal Dispersion and Catalytic Activity toward Dry Methane Reforming Reaction

Abstract

This work studied the effect of interaction between active metal species (Ni and Ni-Co species) and different support (Al2 O3-MgO and SiO2) on the catalyst properties and catalytic performance in dry methane reforming reaction. Supports were synthesized by sol-gel method, then the catalyst samples were prepared by incipient wetness impregnation with a salt solution of active metal(s). The fresh catalysts were characterized via Scanning Electron Microscopy (SEM), Temperature Programmed Reduction (TPR) and Temperature Programmed Desorption (TPD) techniques. Dry Methane Reforming (DMR) activities were tested in a conventional fixed-bed reactor at 620°C. The SEM images and H2-TPR results reveal that the Strong Metal Support Interaction (SMSI) takes place in the catalysts based on Al2 O3-MgO support. The metal dispersion and average metal particle size were evaluated using TPD results. It was found that a Ni-Co bimetallic catalyst provides higher metal dispersion and smaller average metal particle size than Ni monometallic catalysts due to the effect of metal-metal interaction. The bimetallic catalyst with weaker metal-support interaction improve the metal-metal interaction resulting in increasing higher metal dispersion. DMR test presented that sites of strong metal-support interaction enhanced CH4 activity. The stronger metal-metal interaction in Ni-Co bimetallic catalyst with SiO2 support promoted CO2 activity.