Catalyzed Oxidation of Methanol on Acid/Base Modified VOx/Al2O3 Studied by Solid-state NMR
改性VOx/Al2O3催化剂催化氧化甲醇的固体核磁共振研究

Oxidation of methanol catalyzed by NaOH or HNO3 modified VOx/Al2O3 was studied by solid-state nuclear magnetic resonance (NMR) spectroscopy. The acid-treated VOx/Al2O3 catalyst showed stronger Bronsted acid sites compared to the unmodified VOx/Al2O3 catalyst, while the base-treated VOx/Al2O3 catalyst had no Bronsted acid sites. As a result, the former exhibited higher selectivity in producing dimethoxymethane from oxidation of methanol whereas the oxidation reaction catalyzed by the later yielded mainly formate. These results indicate that the Bronsted acid sites in VOx/Al2O3 catalysts play a key role in the oxidation reaction converting methanol to dimethoxymethane.