Surface and interfacial engineering of heterogeneous metal catalysts is effective and critical for optimizing selective hydrogenation for fine chemicals. By using thiol-treated ultrathin Pd nanosheets as a model catalyst, we demonstrate the development of stable, efficient, and selective Pd catalysts for semihydrogenation of internal alkynes. In the hydrogenation of 1-phenyl-1-propyne, the thiol-treated Pd nanosheets exhibited excellent catalytic selectivity (>97%) toward the semihydrogenation product (1-phenyl-1-propene). The catalyst was highly stable and showed no obvious decay in either activity or selectivity for over ten cycles. Systematic studies demonstrated that a unique Pd-sulfide/thiolate interface created by the thiol treatment was crucial to the semihydrogenation. The high catalytic selectivity and activity benefited from the combined steric and electronic effects that inhibited the deeper hydrogenation of C=C bonds. More importantly, this thiol treatment strategy is applicable to creating highly active and selective practical catalysts from commercial Pd/C catalysts for semihydrogenation of internal alkynes.

非均相金属催化剂的表面和界面工程对于优化精细化学品的选择性加氢是有效和关键的。通过使用硫醇处理的超薄钯纳米片作为模型催化剂，我们证明了用于内部炔烃半加氢的稳定，有效和选择性的钯催化剂的发展。在1-苯基-1-丙炔的氢化中，硫醇处理的Pd纳米片对半氢化产物（1-苯基-1-丙烯）表现出优异的催化选择性（> 97％）。该催化剂是高度稳定的，并且在十个循环中没有显示出明显的活性或选择性下降。系统研究表明，通过硫醇处理产生的独特的Pd-硫化物/硫醇盐界面对半氢化至关重要。高的催化选择性和活性得益于空间和电子效应的结合，抑制了C = C键的加氢作用。更重要的是，这种硫醇处理策略适用于从商业Pd / C催化剂制备高活性和选择性的实用催化剂，以进行内部炔烃的半加氢反应。