Dry Reforming of Methane over Ni-Supported SBA-15 Prepared with Physical Mixing Method by Complexing with Citric Acid.

Ni-supported SBA-15 catalysts were prepared by physical mixing of Ni(NO₃)₂·6H₂O and SBA-15 (Ni/SBA-15-M) and in the presence of citric acid as the complexing agent (Ni/SBA-15-M-C). Moreover, an Ni-supported SBA-15 catalyst was also prepared by the conventional incipient impregnation method (Ni/SBA-15-I). All the catalysts were systematically evaluated for carbon dioxide reforming of methane (CDR) at CO₂/CH₄ = 1.0, gas hourly space velocity of 60,000 mL·g⁻¹·h⁻¹, and reaction temperature of 700 °C. The characterization results show that the Ni particle size of Ni/SBA-15-M-C is significantly smaller than that of Ni/SBA-15-M due to the coordination effect of citric acid and Ni²⁺. Consequently, the Ni/SBA-15-M-C exhibits superior anti-coking and anti-sintering during the CDR-operated period because of the higher Ni dispersion and stronger Ni–support interaction. Compared to the Ni/SBA-15-I, the physical mixing of nickel salt and mesoporous material for preparing of Ni-based catalyst is easy to operate, although the crystal size and catalytic performance of Ni/SBA-15-C are very similar to that of Ni/SBA-15-M-I. Thus, the efficient and easily controlled catalyst structure makes the physical mixing strategy very promising for preparing highly active and stable CDR catalysts. [ABSTRACT FROM AUTHOR]