中国科学院大连化学物理研究所团队报道了陈萍钯钙络合氢化物催化炔烃半氢化成烯烃。相关研究成果于2021年12月2日发表于国际顶尖学术期刊《美国化学会杂志》。

炔烃选择性加氢制烯烃需要一个具有合适电子性质的催化中心，以调节炔烃、烯烃以及二氢化物的吸附和转化。

该文中，研究人员报道了一种复杂的钯氢化物，CaPdH₂，其特征是富电子[PdH₂]δ位点被Ca阳离子包围，Ca阳离子通过与Pd的σ^-键和不寻常的阳离子π与Ca相互作用与C₂H₂和C₂H₄相互作用，导致比Pd金属催化剂更弱的化学吸附。同时，H₂的解离和C₂H_x（x=2–4）物种的氢化在CaPdH₂上经历了显著的能量屏障，与已报道的钯基催化剂有根本不同。该独特的催化环境使第一种复杂的过渡金属氢化物催化剂CaPdH₂能够为炔烃的半加氢提供高的烯烃选择性。

附：英文原文

Title: Enabling Semihydrogenation of Alkynes to Alkenes by Using a Calcium Palladium Complex Hydride

Author: Qing Guo, Ruting Chen, Jianping Guo, Chao Qin, Zhitao Xiong, Hanxue Yan, Wenbo Gao, Qijun Pei, Anan Wu, Ping Chen

Issue&Volume: December 2, 2021

Abstract: Selective hydrogenation of alkynes to alkenes requires a catalytic site with suitable electronic properties for modulating the adsorption and conversion of alkyne, alkene as well as dihydrogen. Here, we report a complex palladium hydride, CaPdH2, featured by electron-rich [PdH2]δ sites that are surrounded by Ca cations that interacts with C2H2 and C2H4 via σ-bonding to Pd and unusual cationπ interaction with Ca, resulting in a much weaker chemisorption than those of Pd metal catalysts. Concomitantly, the dissociation of H2 and hydrogenation of C2Hx (x = 2–4) species experience significant energy barriers over CaPdH2, which is fundamentally different from those reported Pd-based catalysts. Such a unique catalytic environment enables CaPdH2, the very first complex transition-metal hydride catalyst, to afford a high alkene selectivity for the semihydrogenation of alkynes.

DOI: 10.1021/jacs.1c09489

Source: https://pubs.acs.org/doi/10.1021/jacs.1c09489