Transition metal (Cu, Cr, and V) modified MCM-41 for the catalytic wet air oxidation of aniline

Mesoporous MCM-41 based materials containing various transition metals (Cr, Cu and V) were prepared hydrothermally and characterized using various analytical and spectroscopic techniques. Cr and Cu are randomly anchored to the surface of MCM-41 support, while V is predominantly present as penta-valent species within the framework structure of the support. The catalytic activity was tested in the wet air oxidation of aniline aqueous solutions (2 g/L) using a high-pressure reactor at 200 °C with an oxygen partial pressure of 6.9 bar. Among the prepared materials, (Cu)MCM-41 showed a significant catalytic activity with an aniline conversion after 2 h of 96% and a selectivity towards CO2 formation of 76%. Although some leaching of the Cu was observed, the catalyst showed a good performance and stability after re-use in at least three consecutive cycles.