Enhanced catalytic performance of Ni/SBA-15 towards CO2 methanation via P123-assisted method

Abstract

This study focused on the enhancement of catalytic performance of Ni/SBA-15 towards CO2 methanation via P123(PEG-PPG-PEG triblock copolymer)-assisted impregnation method. The physical and chemical properties of the catalysts were characterized using XRD, BET, TEM, and FTIR, meanwhile the catalytic performance of catalysts towards CO2 methanation were evaluated using stainless steel fixed bed reactor. The presence of coke on the surface of catalysts was characterized using TGA analysis. XRD, BET and TEM results revealed that the dispersion of Ni particles on the surface of SBA-15 were improved with P123 (Ni/SBA-15(P123)) as compared to without P123 (Ni/SBA-15). FTIR analysis revealed that P123 enhanced the formation of metal-support interaction (Si-O-Ni) through the substitution of O-H with O-Ni. Ni/SBA-15(P123) exhibited higher catalytic activity with 90.3% CO2 conversion and 97.5% CH4 selectivity, meanwhile Ni/SBA-15 showed lower catalytic activity with 81.6% CO2 conversion and 97.1% CH4 selectivity at temperature of 623 K. Apart from higher catalytic activity, Ni/SBA-15(P123) also showed better stability than that of Ni/SBA-15 whereby no carbon formation detected in TGA analysis for 48 h time on stream. The promising performance of Ni/SBA-15(P123) associated to its smaller metal particles, stronger metal-support interaction and more homogeneous metal dispersion, which altered the properties of catalyst towards an excellent catalytic performance. This study provides new perspective on the beneficial effect of P123-assisted impregnation method in the enhancement of catalytic performance of Ni/SBA-15 towards CO2 methanation.