Au–Cu bimetallic nanoparticles with uniform size, shape, and compositions were synthesized by wet chemistry method, and then the Au–Cu/SiO 2 catalyst supported on SiO 2 was prepared. Meanwhile, their catalytic activity for the selective oxidation of propene to acrolein using O 2 as an oxidant was evaluated. The bimetallic catalyst shows a significantly enhanced catalytic performance comparing with Au and Cu monometallic catalysts. Characterization of the materials and kinetic study was conducted to explore the cooperating mechanism of Au and Cu for improving the catalytic activity of the bimetallic catalyst. Cu component can segregate to the alloy surface and the Au–Cu alloy transferred to Au–CuO core/shell structure after annealing during the preparation process. Based on the Mars–van Krevelen mechanism for the selective oxidation of propene over the prepared catalysts, the coexistence of CuO can promote the adsorption and activation of O 2 . Meanwhile, the electrons transfer from Au to Cu in the catalyst can facilitate the adsorptions of both oxygen on CuO sites and propene on Au sites. The combined effects of the above two aspects result in the high catalytic activity of the Au–Cu/SiO 2 catalyst for selective oxidation of propene to acrolein, compared to the Au/SiO 2 and CuO/SiO 2 catalysts. Graphical abstract

中文翻译：

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在双金属 Au-Cu/SiO2 催化剂上增强用 O2 选择性氧化丙烯的催化性能

采用湿化学法合成了尺寸、形状和成分均一的Au-Cu双金属纳米粒子，然后制备了负载在SiO 2 上的Au-Cu/SiO 2 催化剂。同时，评估了它们使用O 2 作为氧化剂将丙烯选择性氧化成丙烯醛的催化活性。与 Au 和 Cu 单金属催化剂相比，双金属催化剂显示出显着增强的催化性能。对材料进行表征和动力学研究，以探索 Au 和 Cu 协同提高双金属催化剂催化活性的机制。Cu组分可以偏析到合金表面，并且在制备过程中退火后Au-Cu合金转移到Au-CuO核/壳结构。基于在制备的催化剂上选择性氧化丙烯的 Mars-van Krevelen 机制，CuO 的共存可以促进 O 2 的吸附和活化。同时，催化剂中从 Au 到 Cu 的电子转移可以促进 CuO 位点上的氧和 Au 位点上的丙烯的吸附。与Au/SiO 2 和CuO/SiO 2 催化剂相比，上述两个方面的综合作用导致Au-Cu/SiO 2 催化剂对丙烯选择性氧化成丙烯醛的催化活性更高。图形概要 与Au/SiO 2 和CuO/SiO 2 催化剂相比，上述两个方面的综合作用导致Au-Cu/SiO 2 催化剂对丙烯选择性氧化成丙烯醛的催化活性更高。图形概要 与Au/SiO 2 和CuO/SiO 2 催化剂相比，上述两个方面的综合作用导致Au-Cu/SiO 2 催化剂对丙烯选择性氧化成丙烯醛的催化活性更高。图形概要