Influence of the Reducing Atmosphere on the Structure and Activity of Mo-V-Te-Nb-O Catalysts for Propane Selective Oxidation

The effects of the addition of the reductant (ammonium chloride) on Mo-V-Te-Nb-O mixed oxide catalysts for propane selective oxidation to acrylic acid were systematically investigated. The presence of the reductant during catalyst preparation had a significant impact on the mobility of lattice oxygen mainly responsible for the catalytic activity of the Mo-V-Te-Nb-O catalysts. Furthermore, the addition of the reductant resulted in clear changes in catalyst morphology and phase composition, which are important factors in the formation of acrylic acid. A high content of the orthorhombic M1 phase led to a high selectivity to acrylic acid at low temperatures (< 653 K), while a high content of the hexagonal M2 phase promoted the formation of acrylic acid at high temperatures (> 653 K).