Study on the Effect of Nickel Doping on Mo-Bi Based Catalyst for Selective Oxidation of Isobutene to Methacrolein

Abstract

Abstract Small amount of different nickel precursors (nickel nitrate or nickel molybdate) were incorporated into MoBi-based catalyst to produce a series of modified composite oxides catalysts for the selective oxidation of isobutene (IB) to methacrolein (MAL). Nickel nitrate introduction can effectively improve IB conversion and nickel molybdate introduction can remarkably enhance the selectivity of MAL. The XRD results show that nickel introduction has some influence on the catalyst structure. The catalyst modified with NiMoO4 showed the highest MAL yield of 87.8%. According to the H2-TPR, BET and XPS results, the catalyst modified with NiMoO4 exhibits lower reduction temperature, higher pore volume and better lattice oxygen mobility, which were confirmed to be responsible for excellent catalytic performance for the title reaction. In the case of an excess of O2, an empirical kinetic model was used to evaluate the rate data. The activation energy (Ea) was found to be 172.4 kJ mol−1.