Improving the Activity and Stability of YSZ-Supported Gold Powder Catalyst by Means of Ultrathin, Coherent, Ceria Overlayers. Atomic Scale Structural Insights

A Au(0.85 wt %)/YSZ catalyst was prepared through a deposition-precipitation method and afterward modified with the addition of a very slight amount of CeO2 (3.7 wt %) by incipient wetness impregnation. A prior electron microscopy characterization points out that both catalysts, Au(0.85 wt %)/YSZ and CeO2(3.7 wt %)/Au(0.85 wt %)/YSZ, exhibit a similar Au nanoparticle distribution with most particles below 5 nm. The CO oxidation reaction was tested over these catalysts in a heating–cooling cycles experiment, which evidenced a much better stability of the CeO2-modified sample against deactivation under very harsh temperature conditions. The characterization of the catalysts after reaction indicates that the sintering effect of the Au nanoparticles is quite similar in both cases, suggesting the key role of specific interactions between Au and CeO2 on the performance of the surface modified catalyst. An in-depth aberration correction electron microscopy study, combining imaging and analytical techniques, allo...