Dry reforming of methane over CeO2 supported Ni, Co and Ni-Co catalysts

Ceria supported Ni, Co monometallic and Ni-Co bimetallic catalysts were prepared by incipient wetness impregnation method, calcined at two different temperatures (700 degrees C and 900 degrees C) and tested for dry reforming of methane reaction at 700 degrees C. The activities of ceria-based Ni containing catalysts decreased with increasing calcination temperature accompanied by a decrease in coke deposition. While Ni/CeO2 and Ni-Co/CeO2 catalysts exhibited comparable high activities, Co/CeO2 catalysts exhibited very low activity. The lower activity of Co/CeO2 catalyst was attributed to strong metal support interaction (SMSI). The SMSI effect was confirmed with TEM images showing a layer of support coating the metal particles. The diversity of the deposited carbon structures in terms morphology (straight long filaments, highly entangled and curly shaped filaments, filaments with knuckle-like structure and carbon onions) was noted. In addition to the carbon buildup, the deactivation was observed to be due to the loss of active metals in the carbon filaments