N-Oxyl Radicals Trapped on Zeolite Surface Accelerate Photocatalysis

The zeolite materials have been industrially used in the thermal catalysis, but their function in photocatalysis has not been fully explored. Here we report that zeolites as supports could strengthen the radical formation after loading ferric oxide nanoparticles (FeOx/zeolite) under photoirradiation: Multiple theoretical and experimental studies demonstrate that the N-hydroxyphthalimide (NHPI) molecules could be trapped within the orifice of MFI zeolites via a sterically controllable adsorption, weakening the NO-H bonding to boost the phthalimide-N-oxyl radial (PINO center dot) formation. The formed radicals could activate the carbon-hydrogen bonds for accelerating the hydrocarbon oxidation into the corresponding ketones/carboxylic acids.