Yamada Takehiro, Kuwahara Yasutaka, Yamashita Hiromi
Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Osaka 565-0871, Japan.
Innovative Catalysis Science Division, Institute for Open and Transdisciplinary Research Initiatives (OTRI), Osaka University, 2-1 Yamada-oka, Suita 565-0871, Osaka, Japan.
ACS Appl Mater Interfaces. 2025 Apr 30;17(17):25267-25277. doi: 10.1021/acsami.4c22713. Epub 2025 Apr 21.
Reverse water-gas shift (RWGS) reaction is a promising strategy for the effective valorization of CO. Because of its endothermic nature, a high-performance catalyst with high durability at high temperatures has been required. Herein, we reveal the dynamic structural changes of platinum-loaded molybdenum suboxide catalysts (Pt/MoO) in RWGS reaction by multiple and measurements, and the catalyst exhibits high activity and CO selectivity, as well as high stability at 500 °C due to the emergence of contiguous Mo species (Mo--Mo) and the strong metal-support interaction (SMSI) effect in MoO. X-ray absorption fine structure (XAFS) measurements demonstrated that the RWGS reaction is driven by reversible redox of -formed MoO suboxide, where the contiguous Mo--Mo species in MoO act as activation sites for CO. Comprehensive analysis revealed that the MoO shell surrounding the Pt nanoparticles (NPs) suppresses CO adsorption, thereby resulting in high CO selectivity. Furthermore, the catalyst exhibited a continuous activity increase in the earlier stage of operation at 500 °C, which was attributed to the partial carburization of MoO during the reaction and the associated increase in the electron density of the Mo species. These findings advance the understanding of RWGS reaction mechanism and suggest innovative strategies for the development of high-performance oxide catalysts with enhanced stability.
逆水煤气变换（RWGS）反应是一种很有前景的有效利用CO的策略。由于其吸热性质，需要一种在高温下具有高耐久性的高性能催化剂。在此，我们通过多种测量手段揭示了负载铂的氧化钼亚氧化物催化剂（Pt/MoO）在RWGS反应中的动态结构变化，该催化剂由于在MoO中出现连续的Mo物种（Mo--Mo）以及强金属-载体相互作用（SMSI）效应，在500°C时表现出高活性、高CO选择性以及高稳定性。X射线吸收精细结构（XAFS）测量表明，RWGS反应是由形成的氧化钼亚氧化物的可逆氧化还原驱动的，其中MoO中的连续Mo--Mo物种充当CO的活化位点。综合分析表明，围绕铂纳米颗粒（NPs）的MoO壳层抑制了CO吸附，从而导致高CO选择性。此外，该催化剂在500°C运行的早期阶段活性持续增加，这归因于反应过程中MoO的部分渗碳以及Mo物种电子密度的相应增加。这些发现增进了对RWGS反应机理的理解，并为开发具有更高稳定性的高性能氧化物催化剂提出了创新策略。
