New insights into the size and support effects of γ-Al2O3 supported Au catalysts for HCHO oxidation at room temperature

Abstract

Strong metal support interaction (SMSI) between Au nanoparticles (NPs) and a non-reducible γ-Al₂O₃ support was revealed to affect HCHO oxidation at room temperature. Catalyst characterization by HRTEM and ²⁷Al NMR revealed that Au NPs were encapsulated by the γ-Al₂O₃ support and that pentacoordinate Al³⁺ ions on the γ-Al₂O₃ surface acted as anchoring sites for Au nanoparticles. The SMSI in Au/γ-Al₂O₃ not only enhanced the dispersion of the Au NPs but also stabilized the NPs during the reaction. As a result, Au/γ-Al₂O₃ with strong SMSI exhibited high initial activity and stability in HCHO oxidation at room temperature. These findings provide new insights into the Au NP size and support effects of Au/γ-Al₂O₃ catalysts used for HCHO oxidation at room temperature.