hcp晶相的Ni纳米颗粒对不同官能团的通用催化加氢活性

hcp-phased Ni nanoparticles with generic catalytic hydrogenation activities toward different functional groups

催化加氢是生产高附加值燃料和精细化学品的重要工业途径,但需要高效的催化剂,尤其是廉价的非贵金属催化剂.迄今为止,大多数高性能催化加氢催化剂都是由贵金属材料制成,并且这些催化剂都只能用于催化一种或几种特定的反应.在这里,我们例证了一种晶相工程方法,其能赋予Ni纳米颗粒(NPs)卓越的、广谱的内在催化加氢活性.这种负载于碳载体上含有hcp晶相的Ni NPs催化剂通过直接碳化热解Ni咪唑MOF前驱体获得.在纯水中,含hcp相的Ni NPs对硝基、醛、酮、烯烃和N杂环化合物表现出前所未有的加氢催化活性,优于类似物fcc-Ni和目前报道的其他过渡金属催化剂.密度泛函理论计算表明,hcp-Ni通过增强底物吸附强度和降低速率决定步骤的反应势垒能共同来提高内在催化氢化活性.我们预计这项工作中揭示的晶相工程设计方法将适用于其他类型的反应.

Catalytic hydrogenation is a vital industrial means to produce value-added fuels and fine chemicals,however, requiring highly efficient catalysts, especially the nonprecious ones. To date, the majority of high-performance industrial hydrogenation catalysts are made of precious metals-based materials, and any given catalyst could only be used to catalyze one or few specific reactions. Herein, we exemplify a crystal phase engineering approach to empower Ni nanoparticles(NPs) with superb intrinsic catalytic activities toward a wide spectrum of hydrogenation reactions. A facile pyrolysis approach is used to directly convert a Ni-imidazole MOF precursor into hexagonal close-packed(hcp)-phased Ni NPs on carbon support. The as-synthesized hcp-phased Ni NPs exhibit unprecedented hydrogenation catalytic activities in pure water towards nitro-, aldehyde-, ketone-, alkene-and N heterocyclic-compounds, outperforming the face-centered cubic(fcc)-Ni counterpart and the reported transition metalsbased catalysts. The density functional theory calculations unveil that the presence of hcp-Ni boosts the intrinsic catalytic hydrogenation activity by coherently enhancing the substrate adsorption strength and lowering the reaction barrier energy of the rate-determining step. We anticipate that the crystal phase engineering design approach unveiled in this work would be adoptable to other types of reactions.