Tailoring the electronic states of Pt by atomic layer deposition of Al2O3 for enhanced CO oxidation performance: Experimental and theoretical investigations

• Published in: Applied catalysis. B, Environmental Environmental, 2023-09, Vol.333, p.122804, Article 122804
• Main Authors: Hu, Siyuan, Huang, Mingzhen, Li, Jingru, He, Jinxin, Xu, Kaiji, Rao, Xiaoping, Cai, Dongren, Zhan, Guowu
• Format: Article
• Language: English
• Subjects: Atomic layer deposition; CO oxidation; Density functional theory; Metal-organic framework; Pt catalyst
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2023.122804

Herein, atomic layer deposition (ALD)-Al2O3 films were applied as a medium to modulate the electronic states of the supported Pt. Based on the sacrificial template of ZIF-67, the ternary Co3O4/Pt/Al2O3 catalyst exhibited better performance in catalytic CO oxidation than the binary Co3O4/Pt catalyst. Both experimental and calculation results indicate the existence of charge transport between the Pt and the ALD-Al2O3 films, leading to electron-rich Pt, enhanced O2 affinity, and reduced activation energy. Interestingly, the oxidation resistance of Pt nanoparticles was visualized when annealing Co3O4/Pt/Al2O3 catalyst at high temperatures. Mechanism studies indicate the typical LH mechanism occurred in CO oxidation, showing that the co-adsorbed CO and O2 could be converted to carbonate-type *OCOO intermediates via low energy barriers. At low temperatures, CO2 was mainly produced by the lattice oxygen-mediated M-vK mechanism based on isotope labeling experiments. Our findings provide an alternative way to regulate the electronic states of noble metals by the ALD technique. [Display omitted] •A series of ternary Co3O4/Al2O3/Pt catalysts were prepared using MOF as precursor.•The ALD-Al2O3 film was used to modulate the electronic state of Pt.•Pt modified with Al2O3 had a stronger affinity for O2, leading to high performance.•Sandwiched Co3O4/Pt/Al2O3 showed the best performance in catalytic CO oxidation.•DFT and isotope labeling experiments were used to explore the reaction mechanism.