The complicated reaction pathway of the water–gas shift reaction (WGSR) hinders understanding the overall reaction mechanism and extracting the factors to design better performing catalysts. Here, we use density functional theory to study the mechanism of WGSR catalyzed by Au single atoms stabilized at the CeO_x–TiO₂ interfaces on TiO₂ particles (ACT catalyst). We constructed two energetic landscapes of the WGSR (redox and associative mechanisms), concurrently presenting the H₂ formation as a rate-determining step. Electronic analysis data showed that the charge state of the oxygen ions participating in WGSR strongly correlates with the oxygen vacancy formation energy (OVF) and hydrogen binding energy (ΔE_H), directly scaling the CO oxidation power and the H₂ production ability. Further expansion toward various Au on oxide–oxide combinations confirmed that the delicate control of metal-oxide-oxide interfaces with optimized local electronic structures expresses the rational design of a WGSR catalyst.

中文翻译：

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多元氧化物负载Au单原子催化水煤气变换反应活性的控制机制


水煤气变换反应（WGSR）复杂的反应路径阻碍了理解整体反应机理并提取因素来设计性能更好的催化剂。在这里，我们利用密度泛函理论研究了稳定在 TiO ₂ 颗粒上的 CeO _x -TiO ₂ 界面上的 Au 单原子催化 WGSR 的机理（ ACT 催化剂）。我们构建了 WGSR 的两个能量景观（氧化还原机制和缔合机制），同时将 H ₂ 形成作为速率决定步骤。电子分析数据表明，参与WGSR的氧离子的电荷态与氧空位形成能(OVF)和氢结合能(ΔE _H )密切相关，直接缩放CO氧化功率和H2 ₂ 生产能力。对氧化物-氧化物组合上各种金的进一步扩展证实，通过优化局部电子结构对金属-氧化物-氧化物界面的精细控制体现了WGSR催化剂的合理设计。