The characteristics of hydrogen spillover on various metal oxides, involving the concurrent diffusion of protons (H⁺) and electrons (e⁻), were systematically studied by combining in situ analytical techniques with kinetic analyses. H₂-temperature programmed reduction and in situ X-ray absorption fine structure data showed that hydrogen spillover from Pt onto TiO₂ and WO₃ greatly decreased the temperatures at which Zn²⁺ ions deposited on these remote metal oxides were reduced. In contrast, hydrogen spillover on MgO and CeO₂ did not significantly affect the reduction of remote Zn²⁺. Mechanisms explaining the effects of spilled hydrogen on reduction for each oxide substrate were proposed based on the dynamic behaviors of H⁺ and e⁻ as ascertained by means of in situ spectroscopic characterizations and kinetic analyses. The results of this work indicate that e⁻ diffusion rather than H⁺ diffusion promotes the reduction of deposited metal ions and that interparticle hydrogen spillover can be facilitated over TiO₂ and WO₃ as a consequence of the interfacial diffusion of H⁺ and e⁻ pairs. These findings provide an improved understanding of the hydrogen spillover phenomenon.

中文翻译：

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氧化物平台对氢溢出动力学和还原特性的影响


通过将原位分析技术与动力学分析相结合，系统研究了氢溢出在各种金属氧化物上的特性，包括质子 （H⁺） 和电子 （e^--） 的同步扩散。H₂ 温度程序还原和原位 X 射线吸收精细结构数据表明，氢从 Pt 溢出到 TiO₂ 和 WO₃ 上大大降低了沉积在这些远程金属氧化物上的 Zn²⁺ 离子降低的温度。相比之下，氢溢出对 MgO 和 CeO₂ 没有显着影响远程 Zn²⁺ 的还原。根据通过原位光谱表征和动力学分析确定的 H⁺ 和 e^-的动力学行为，提出了解释溢出氢对每种氧化物衬底还原影响的机制。这项工作的结果表明，e⁻ 扩散而不是 H⁺ 扩散促进了沉积金属离子的还原，并且由于 H⁺ 和 e⁻ 对的界面扩散，可以促进 TiO₂ 和 WO₃ 上的粒子间氢溢出。这些发现为更好地了解氢溢出现象提供了更好的理解。