Catalytic hydrogenation of maleic anhydride to γ-butyrolactone over a high-performance hierarchical Ni-Zr-MFI catalyst

High-performance MFI zeolite supported nickel catalysts were prepared by the ammonia evaporation method for maleic anhydride (MA) conversion to γ-butyrolactone (GBL). According to comprehensive characterizations, the Ni catalysts possessed petal-like morphology and hierarchical structures with meso and micro pores. Nickel species were highly dispersed on the silica support and generated abundant Lewis acid sites (LAS), which effectively activated carbonyl groups in the reactant and accounted for the high activity in MA hydrogenation. Zr species hydrothermally introduced into the catalyst increased the number of LAS and decreased the apparent activation energy for the reaction. The highest GBL yield reached 95.6% over 40Ni-2Zr-MFI with the assistance of 3A zeolite to in-situ remove water byproduct. The catalyst showed reasonably good stability in five-cycle operation thanks to the strong interaction between Ni and support. The reaction route for MA hydrogenation was investigated, in which succinic anhydride (SA-A) served as the major reaction intermediate for GBL formation.