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