Methanol is oxidized to methyl formate, but not to formaldehyde, over SnO 2-MoO 3 catalysts. Tests of various binary-oxide catalysts indicated that the best results for both activity and selectivity were obtained with the Sn/Mo atomic ratio = 7/3 catalyst. It was proposed that methyl formate is formed via formaldehyde as follows: 2 CH 3OH → 2 HCHO → HCOOCH 3. It was concluded that the possession of both acidic and basic properties is required to catalyze the reaction.