State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
J Am Chem Soc. 2012 Dec 26;134(51):20585-8. doi: 10.1021/ja310341j. Epub 2012 Dec 13.
Au/CeO(2) catalysts are highly active for low-temperature CO oxidation and water-gas shift reaction, but they deactivate rapidly because of sintering of gold nanoparticles, linked to the collapse or restructuring of the gold-ceria interfacial perimeters. To date, a detailed atomic-level insight into the restructuring of the active gold-ceria interfaces is still lacking. Here, we report that gold particles of 2-4 nm size, strongly anchored onto rod-shaped CeO(2), are not only highly active but also distinctively stable under realistic reaction conditions. Environmental transmission electron microscopy analyses identified that the gold nanoparticles, in response to alternating oxidizing and reducing atmospheres, changed their shapes but did not sinter at temperatures up to 573 K. This finding offers a new strategy to stabilize gold nanoparticles on ceria by engineering the gold-ceria interfacial structure, which could be extended to other oxide-supported metal nanocatalysts.
Au/CeO2 催化剂在低温 CO 氧化和水汽变换反应中具有很高的活性,但由于金纳米颗粒的烧结,导致其迅速失活,这与金-铈界面周长的坍塌或重构有关。迄今为止,对于活性金-铈界面的重构,仍缺乏详细的原子水平的深入了解。在这里,我们报告了尺寸为 2-4nm 的金颗粒,强锚定在棒状 CeO2 上,不仅具有很高的活性,而且在实际反应条件下也具有明显的稳定性。环境透射电子显微镜分析表明,金纳米颗粒在交替的氧化和还原气氛中,其形状发生了变化,但在高达 573K 的温度下并未烧结。这一发现为通过工程化金-铈界面结构来稳定氧化铈上的金纳米颗粒提供了一种新策略,该策略可扩展到其他氧化物负载的金属纳米催化剂。