The Effect of LaPO4 Crystal Morphology on Gas-Phase Catalytic Synthesis of Anisole

The gas-phase synthesis of anisole from methanol and phenol is currently recognized as the process with the most theoretical research value and industrial application prospect. LaPO4has attracted widespread attention due to its excellent catalytic activity, robust water resistance, and high-temperature performance. In this work, rod-like monoclinic, mixed phase, and hexagonal LaPO4were synthesized using the hydrothermal method, and their catalytic activity was evaluated. The results showed that the catalytic activity of the hexagonal phase is higher than that of the monoclinic phase. By combining relevant characterization methods and DFT theoretical calculations, it is clarified that the higher acidity and stronger alkalinity of the exposed surface of hexagonal LaPO4are the main reasons for its higher activity. Further research has revealed that the main cause of LaPO4deactivation is carbon deposition on the catalyst surface.