Promoter Effect on Ni/SiO2 Catalysts for Acetylene Semi-hydrogenation to Ethylene.

Bimetallic catalysts have widespread applications in many reactions. Series of Ni/SiO₂ catalysts containing different promoters were prepared by ammonia evaporation method in this work. The effect of Sn and Mg additives on the catalytic performance of nickel-based catalysts in acetylene hydrogenation was investigated. The introduction of Mg additives led to the over-hydrogenation of acetylene to ethane, vs. the Sn promoter increases the selectivity of the catalysts towards ethylene. The Ni₇Sn/SiO₂ showed the most superior catalytic performance. The effects of different additives on the active metals were investigated through a series of characterizations and thus the structure-performance relationship was well investigated. Reaction mechanism diagram of acetylene and hydrogen over Ni/SiO₂ based catalysts. [ABSTRACT FROM AUTHOR]