【摘要】 CO₂甲烷化反应在大规模CO₂利用、可再生能源存储等方面有很好的应用前景.研究开发高活性、高稳定性的CO₂甲烷化催化剂已成为研究热点.负载型钌基催化剂对CO₂甲烷化反应具有高活性和高稳定性,因此被广泛关注.此类催化剂在甲烷化反应过程中表现出结构敏感性,其中钌催化剂的尺寸与结构、催化剂载体、钌催化剂与载体之间的强相互作用等,均对催化剂催化活性和反应机理影响较大.目前,负载型钌基催化剂的结构可控制备是目前面临的主要挑战.本文总结了近年来负载型钌基催化剂在CO₂甲烷化反应领域的研究进展,并对后续研究发展作了展望.首先,对CO₂甲烷化做了热力学分析,说明低温、高压和高氢/碳比有利于甲烷的生成,但催化剂在低温下的加氢活性存在一定局限.然后,从催化剂尺寸效应、载体影响以及金属-载体相互作用等方面,对CO₂甲烷化负载型钌基催化剂研究进展进行了分析讨论.归纳总结了钌催化剂尺寸效应,说明单原子钌催化剂对CO₂分子的解离能力不足,负载型单原子钌催化剂更倾向于发生逆水煤气变换反应而生成CO.相比之下,较大尺寸的钌催化剂更利于CO₂甲烷化反应.此外,还讨论了负载型钌基催化剂的载体特性对于甲烷化活性和选择性的影响,包括载体的还原性、表面羟基覆盖度等,也归纳了近年来在非氧化物载体应用等方面的研究进展.论文进一步重点讨论了负载型钌基催化剂中的金属-载体强相互作用对催化剂活性的影响.尽管近年来在负载型钌基CO₂甲烷化催化剂的制备和表征等方面取得了一些进展,但在催化剂低温活性改进、催化剂结构可控制备以及催化反应机理研究等方面仍然存在不足.因此,后续亟需结合先进的催化剂表征手段和理论计算研究方法,有针对性地开展多学科交叉研究.综上,本文对今后CO₂甲烷化负载型钌基催化剂研究有参考意义.更多还原

【Abstract】 CO₂ methanation has a potential in the large-scale utilization of carbon dioxide. It has also been considered to be useful for the renewable energy storage. The commercial pipeline for natural gas transportation can be directly applied for the methane product of CO₂ methanation. The supported ruthenium（Ru） catalyst has been confirmed to be active and stable for CO₂ methanation with its high ability in the dissociation of hydrogen and the strong binding of carbon monoxide. CO₂ methanation over the supported Ru catalyst is structure sensitive. The size of the Ru catalyst and the support have significant effects on the activity and the mechanism. A significant challenge remained is the structural controllable preparation of the supported Ru catalyst toward a sufficiently high low-temperature activity. In this review, the recent progresses in the investigations of the supported Ru catalysts for CO₂ methanation are summarized. The challenges and the future developments are also discussed.更多还原