Synergistic enhancement of size and electronic effects in Ni-based catalysts via Ni–Al interfacial interaction modulation for N-ethylcarbazole hydrogenation

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. The synergistic enhancement mechanism, which is regulated by the Ni–Al interfacial interactions and the anchoring effect of precursors, is systematically investigated with respect to the influence on the size and electronic structure of active metal nanoparticles, as well as on the catalytic performance in N-ethylcarbazole (NEC) hydrogenation. The results show that the optimized Ni/Ni 1 Al 2 -MMO-500 catalyst achieved both small size and high electron density of active metal particles. 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/Al 2 O 3 , with high catalytic performance sustained across five NEC hydrogenation cycles.