Selective Oxidation of Diphenylmethane to Benzophenone over CeAlPO-5 Molecular Sieves

Selective oxidation of diphenylmethane to benzophenone requires active and selective catalysts. The framework incorporation of cerium in AlPO-5 molecular sieves creates active cerium sites in isolation. These active sites are responsible for selective oxidation. Cerium incorporated AlPO-5 with different Al/Ce ratios were synthesized, and the vapor phase oxidation of diphenylmethane in air over these catalysts was studied at 250, 275, 300, 325, and 350°C. The diphenylmethane conversion and selectivity for benzophenone were more than 90%. CeAlPO-5(25) was found to be more active than other catalysts. The stability of the catalyst was verified by the time on stream study which indicated steady diphenylmethane conversion and benzophenone selectivity. Hence framework incorporated CeAlPO-5 molecular sieves are stable and active catalysts for the selective oxidation of diphenylmethane.

Graphical abstractSelective oxidation of diphenylmethane was carried over CeAlPO-5 (Al/Ce = 25, 50, 75, 100, and 125) molecular sieves between 250 and 325°C. The main product of oxidation was benzophenone. The catalytic activity increased with decrease in the Al/Ce ratio of the catalyst.Figure optionsDownload full-size imageDownload as PowerPoint slide