Tuning of the Bimetallic\nCoNi Electronic Structure\nfor Inducing Catalytic Activity and Selectivity for Styrene Hydrogenation

Tuning the selectivity of catalytic hydrogenation is\nof vital importance\nand is challenging in the chemical industry. The present study demonstrates\nthat the highly selective hydrogenation of styrene can be precisely\ncontrolled by simply tuning the reaction temperature over Co<sub><i>x</i></sub>Ni<sub><i>y</i></sub> (<i>x</i> + <i>y</i> = 1) bimetallic nanocatalysts supported on\nSiO<sub>2</sub>. The Co<sub>0.5</sub>Ni<sub>0.5</sub> catalyst exhibits\nmarkedly enhanced catalytic activity, with a styrene conversion that\nis over 4 times higher than that of the pure Ni catalyst and 18 times\nhigher than that of the pure Co catalyst during the initial 1 h. This\noutstanding catalytic performance is comparable to that of Ru and\nPd catalysts, and its selectivity is even more advanced than those\nof some state-of-the-art noble metals. DFT calculations show that\nthe catalytic performance of the bimetallic CoNi catalyst is improved\ndue to the optimized electronic structure of the CoNi alloy. These\nresults suggest that nanosized bimetallic CoNi could be a promising\ncatalyst for the highly selective hydrogenation of CC double\nbonds in unsaturated organic compounds at different positions. Our\nfindings offer useful insights for the design of noble metal-free\nbimetallic nanocatalysts for highly tunable selective hydrogenation\nreactions.