Developing both high-performance and cost-effective hydrogenation catalysts is of strategic importance for advancing the industrialization of liquid organic hydrogen carrier (LOHC) technology. Herein, a series of Ni-based catalysts supported on Ni/Al mixed metal oxides (Ni/NiAl-MMO) are prepared by in-situ topotactic transformation of NiAl-LDH precursors, systematically investigating the synergistic enhancement mechanism regulated by the Ni-Al interfacial interaction and the anchoring effect of the precursor on the size and electronic structure of active metal nanoparticles, as well as their catalytic enhancement effects in N-ethylcarbazole (NEC) hydrogenation. The results show that the optimized Ni/Ni1Al2-MMO-500 catalyst achieved both small size and high electron density of active metal particles under the influence of anchoring effect of the precursor and strong Ni-Al interfacial interaction. The synergistic size and electronic enhancement endow the catalyst with superior catalytic activity in NEC hydrogenation, exceeding all reported Ni-based catalysts and exhibiting catalytic efficiency comparable to that of the widely used commercial precious metal hydrogenation catalyst, 5 wt% Ru/Al2O3, with high catalytic performance sustained across five NEC hydrogenation cycles.
