Propane-selective oxidation was investigated over VMoO alone or over VMoO catalysts promoted by metal ions. Through this reaction, propane was efficiently converted to maleic anhydride, and acetic acid over VMoO itself and over metal-ion-doped VMoO catalysts. Over 70%Mo20%V10%AgO catalyst, 37.4% of propane single pass conversion was obtained at 300 degrees C with maleic anhydride selectivity of 53.6% and acetic acid selectivity of 38.9%. The studies on propylene oxidation indicated that propylene might not be a reaction intermediate for maleic anhydride formation in propane oxidation. A typical carbon-carbon bond cracking and reformation reaction occurred in propane oxidation by using molecular oxygen as oxidant. (c) 2005 Elsevier B.V. All rights reserved.