Morphology effect of ceria supports on gold nanocluster catalyzed CO oxidation. Issue 24 (31st October 2021)

• Record Type: Journal Article
• Authors: Li, Zhimin; Zhang, Xinyu; Shi, Quanquan; Gong, Xia; Xu, Hui; Li, Gao
• Is Part Of: Nanoscale advances. Volume 3:Issue 24(2021)
• Page Start: 7002
• Page End: 7006
• Publication Date: 2021-10-31
• Subjects: 620.5
• DOI: 10.1039/d1na00680k
• Languages: English
• ISSNs: 2516-0230

Abstract

Abstract : The interfacial perimeter is generally viewed as the catalytically active site for a number of chemical reactions over oxide-supported nanogold catalysts. Abstract : The interfacial perimeter is generally viewed as the catalytically active site for a number of chemical reactions over oxide-supported nanogold catalysts. Here, well-defined CeO2 nanocubes, nanorods and nanopolyhedra are chosen to accommodate atomically precise clusters ( e.g. Au25 (PET)18 ) to give different Au cluster–CeO2 interfaces. TEM images show that Au particles of ∼1.3 nm are uniformly anchored on the ceria surface after annealing in air at 120 °C, which can rule out the size hierarchy of nanogold in CO oxidation studies. The gold nanoclusters are only immobilized on the CeO2 (200) facet in Au25 /CeO2 -C, while they are selectively loaded on CeO2 (002) and (111) in the Au25 /CeO2 -R and Au25 /CeO2 -P catalysts. X-ray photoelectron spectroscopy (XPS) and in situ infrared CO adsorption experiments clearly demonstrate that the gold species in the Au25 /CeO2 samples are similar and partially charged (Au δ +, where 0 < δ < 1). It is observed that the catalytic activity decreases in the order of Au/CeO2 -R ≈ Au/CeO2 -P > Au/CeO4 -C in the CO oxidation. And the apparent activation energy over Au25 /CeO2 -C (60.5 kJ mol −1 ) is calculated to be about two-fold of that over the Au25 /CeO2 -R (28.6 kJ mol −1 ) and Au25 /CeO2 -P (31.3 kJ mol −1 ) catalysts. It is mainly tailored by the adsorbed [O] species on the ceria surface, namely, Au25 /CeO2 (002) and Au25 /CeO2 (111) which were more active than the Au25 /CeO2 (200) system in the CO oxidation. These insights at the molecular level may provide guidelines for the design of new oxide-supported nanogold catalysts for aerobic oxidations.