Effect of Adding Phosphorus on Crystal Structure of W‐V‐Nb Complex Oxide and Catalytic Selective Oxidation of Acrolein

The changes in the crystal structure of the W-V-Nb complex oxide with phosphorus addition to the hydrothermal synthesis process are investigated. The effect of the constituent units and crystal structure of phosphorus-added W-V-Nb complex oxide catalysts on the activity and selectivity for selective oxidation of acrolein is discussed. Phosphorus addition to the hydrothermal synthesis process promotes the formation of orthorhombic and trigonal W-V-Nb complex oxides. Orthorhombic and trigonal W-V-Nb complex oxide catalysts give higher acrylic acid selectivity in acrolein oxidation compared to poorly crystalline catalysts that only have {M₆O₂₁} pentagonal units and 7-membered rings.