Vanadium phosphorus oxide catalysts for n-butane selective oxidation toward maleic anhydride: design, modification strategies, and progress

Selective oxidation of n-butane to maleic anhydride (MA) is considered an effective approach to realize the utilization of lighter alkanes into useful chemical products. Currently, vanadium phosphorus oxide (VPO) is the most widely used catalyst for the selective oxidation of n-butane to MA owing to its abundant active sites and oxygen species. However, the development of efficient VPO catalysts remains urgent, as the MA yield is limited by the inherent “trade-off” effect between n-butane conversion and MA selectivity. This review systematically summarizes the progress in the rational design and precise regulation of VPO catalysts, with a particular focus on the influence of physicochemical properties on catalytic performance. More importantly, advanced synthesis routes and modification strategies are discussed in detail. These strategies for modulating the geometric and electronic structures of VPO catalysts are highlighted, accompanied by a discussion of the structure-activity relationship. Finally, the challenges of VPO catalysts are discussed, and future research directions are proposed.