Spontaneous dispersion of metallic nickel centers in inert metal substrate for the selective hydrogenation of carbon-carbon triple bonds

Abstract

Single-site metal catalysts with maximal utilization of active centers and desired target product selectivity represent a hot research topic within the realms of both academic and industry. However, the synthetic strategy is generally complicated and requires the precise control of interplay between metal centers and supporting materials. Herein, a simple spontaneous dispersion and universal strategy are developed to construct all-metal catalyst systems containing isolated metallic centers utilizing the spontaneous dispersion behaviors of transition metal centers Ni in inert substrate (Al, Mg and Ti). Ni/Al and Ni/Mg show remarkable performances in the model reaction of acetylene semi-hydrogenation with state-of-the-art site-specific activity, high ethylene selectivity and good stability. Especially, Ni/Al is reported for the first time to be an eligible low-cost catalyst for the selective hydrogenation of carbon-carbon triple bonds, surpassing the benchmark Lindlar catalyst. The reaction mechanism of acetylene semi-hydrogenation over Ni/Al catalyst is well clarified via the combination of kinetic analyses, spectroscopy investigation and theoretical calculations. The innovative approach developed herein not only expands the synthetic strategies toward single-site metal catalysts but also holds promise for practical applications in diverse chemical transformations due to the intrinsic advantages of all-metal systems.