The size effects of Au and ZrO2 particles on the structural property and the catalytic performance of Au/ZrO2 catalysts for the water gas shift reaction were extensively investigated. It was found that the Au-ZrO2 contact boundaries played essential roles in determining the catalytic reactivity. By keeping the size of Au particle to be ∼3 nm, the increase in the particle size of ZrO2 from ∼7 nm to ∼55 nm caused significant decrease in the reaction rate. When the particle size of ZrO2 was fixed at ∼20 nm, the conversion of CO decreased greatly with increasing the size of gold particle from 2.9 to 6.2 nm. IR spectroscopy and kinetic study revealed that the water gas shift reaction occurred at the Au-ZrO2 contact boundaries, where CO is adsorbed on the Au species and H2O is activated on the surface of ZrO2 through the formation of formate species, acting as key reaction intermediates.

中文翻译：

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用于低温水煤气变换反应的 Au/ZrO2 催化剂：粒径的影响

广泛研究了Au和ZrO2颗粒的尺寸对Au/ZrO2催化剂在水煤气变换反应中的结构性质和催化性能的影响。结果表明，Au-ZrO2 接触边界在决定催化反应性方面起着至关重要的作用。通过将 Au 颗粒的尺寸保持在~3 nm，ZrO2 的粒径从~7 nm 增加到~55 nm 导致反应速率显着降低。当 ZrO2 的粒径固定在~20 nm 时，随着金粒径从 2.9 nm 增加到 6.2 nm，CO 的转化率大大降低。红外光谱和动力学研究表明，水煤气变换反应发生在 Au-ZrO2 接触边界，其中 CO 吸附在 Au 物种上，H2O 通过形成甲酸盐物种在 ZrO2 表面活化，