Polybasic organic acids controlled synthesis of Mo-V-O composite metal oxide for the catalytic conversion of glycerol

By introducing oxalic acid, succinic acid, and tartaric acid into the synthesis process of Mo-V-O composite metal oxides, the structure directing effect of polybasic organic acids on the crystal structure of Mo-V-O compositee metal oxide was studied. Moreover, the prepared Mo-V-O samples with different crystal phase compositions were used to the conversion of glycerol, and the effect of crystal phase structure on its catalytic performance was investigated. Results show that the crystal phase structure of Mo-V-O can be regulated by changing the type and additive amount of polybasic organic acids. The crystal phase of Mo-V-O changed from MoV₂O₈ to Mo_0.97V_0.95O₅ with the increase of succinic acid and tartaric acid. The change in the Mo-V-O crystal phase is related to the amount of organic acid and the carbon chain length. When the crystal phase is MoV₂O₈, the selectivity of acrolein and acetone is 25.7 % and 16.2 %. According to the XPS results, Mo⁶⁺ in MoV₂O₈ promoted the formation of acrolein, while Mo⁵⁺ in Mo_0.97V_0.95O₅ promoted the formation of acetone. So when the crystal phase is Mo_0.97V_0.95O₅, the selectivity of acrolein and acetone is 11.9 % and 24.6 %. Therefore, the results of catalyzing glycerol can be controlled by selecting different crystal phases.