Enhanced metal-support interaction on NiSi-P catalyst for improved COx methanation performance

Abstract

NiSi-I and NiSi-P catalysts were synthesized by impregnation method and ammonia-evaporated method, respectively. They were investigated for COx methanation reaction in the fixed-bed reactor at atmospheric pressure. A series of characterization results demonstrated that the NiSi-P catalyst with phyllosilicates structure achieved superior catalytic performance to the conventional NiSi-I catalyst for COx methanation. Meanwhile, the stability test indicated that CH4 yield on the NiSi-P catalyst decreased slightly from 88.2% to 77.5% at 400 °C after thermal shock at 650 °C for 24 h. However, CH4 yield on the NiSi-I catalyst decreased greatly from 72.5% to 26.7% at the same reaction condition after thermal shock, suggesting that the stability of the NiSi-P catalyst was much better than that of NiSi-I. The superior performance of the NiSi-P catalyst was attributed to several factors including the small nickel particle size, the high Ni surface area, and the enhanced metal-support interaction. These properties contributed to the higher reactivity and better stability of NiSi-P than those of NiSi-I catalyst.