Effect of promoters and calcination temperature on the performance of nickel silica core-shell catalyst in biogas dry reforming

Abstract

In this article, a facile ammonia evaporation method was adopted to synthesize a series of Ni-M-SiO₂@SiO₂ catalysts promoted with Ce, Zr, La, Co and Mg in order to examine the effect of promoters on the catalytic performance of the core-shell catalyst in biogas dry reforming. The obtained outcomes exhibited that rare earth oxide promoted catalyst displayed higher catalytic activity than the unpromoted catalyst. In addition, when the content of cerium oxide increased from 1 wt% to 5 wt% activity of the catalyst increased from 47.5 % to 57.2 % at 600 °C. Acquired results exhibited that, adding 1 wt% cerium oxide to Ni-SiO₂@SiO₂ led to improved dry reforming activity and decreased carbon formation during 12 h dry reforming reaction. 10Ni-1Ce-SiO₂@SiO₂ core-shell catalyst showed higher catalytic activity and lower coke formation than the (10Ni-1Ce)/SiO₂ impregnated catalyst. This observation is because the shell of the catalysts provided steric physical barriers against nickel particles growth, also the nickel phyllosilicate structure posted chemical force that could fix the position of metal particles. The catalytic performance of the catalyst with 1 % cerium oxide was enhanced by enhancing calcination temperature from 700 to 900 °C owing to increase metal-support interaction.