基于简单的水热合成法制备了一系列不同Ir负载量的纳米花状的X% Ir/MoS₂催化剂, 探究其在CO₂加氢反应中的催化活性. Ir/MoS₂催化剂呈现出纳米花状的形貌, 直径大约为800 nm, 纳米花上的二维纳米片分布良好, 这有利于活性位点的充分暴露. Ir的掺杂有效地调整了催化剂的电子结构, 能够使MoS₂局部结构发生相变. 在较低的反应压力下, 1% Ir/MoS₂催化剂表现出了最高的甲酸盐选择性(98%)和活性(8.6 mmol•g^–1•h^–1), 但是过量Ir的负载会导致Ir纳米颗粒发生团聚, 降低了产物的选择性和活性. 1% Ir/MoS₂催化剂还表现出优异的催化稳定性, 在重复使用3次后催化活性没有显著降低. 还通过控制实验对催化机理和反应的溶剂效应进行了研究和讨论. 本研究为开发高性能的CO₂加氢合成甲酸/甲酸盐催化剂提供了一条新的途径.

A series of nanoflower-shaped X% Ir/MoS₂ catalysts with different Ir loadings were prepared based on a simple hydrothermal synthesis method and their catalytic activities in CO₂ hydrogenation were investigated. The Ir/MoS₂ catalyst has a nanoflower-like shape with a diameter of about 800 nm. The layers of two-dimensional nanosheets on the catalyst were well dispersed, which increased the exposure of the active sites. The doping of Ir could effectively tune the electronic structure of the catalyst, causing the local structure phase change of MoS₂. Under low reaction pressure, the 1% Ir/MoS₂ composite showed the highest formate selectivity (98%) and activity (8.6 mmol•g^–1•h^–1). The excessive Ir loading would lead to the agglomeration of Ir to form nanoparticles, which reduced the selectivity and activity of product. The 1% Ir/MoS₂ catalyst also showed excellent catalytic stability, and the catalytic activity did not decrease obviously after being reused three times. Based on control experiments, the catalytic mechanism and solvent effect were also studied and discussed. This study provid es a new way for developing high-performance catalysts for CO₂ hydrogenation to formate.