Zeolites are widely applied in thermal catalysis as highly efficient catalysts but show limited photocatalytic activities. In this work, we demonstrated zeolites as photoactive scaffolds for perovskite nanocrystals that triggered a hydroxyl radical (•OH)-mediated reaction pathway for selective C(sp3)-H bond activation. The as-prepared Cs2AgBiBr6@ZSM-5 (CABB@ZSM-5) photocatalyst afforded efficient toluene oxidation to benzaldehyde at ambient conditions under visible light irradiation, with >98% selectivity and an exceptional reaction rate of 40.9 mmol g-1 h-1, surpassing those of previously reported photocatalytic systems under comparable conditions. The host-guest design of CABB@ZSM-5 favored the adsorption of toluene and oxygen molecules and preactivated the adsorbed toluene molecules by Lewis acidic sites within ZSM-5 to reinforce the oxidation process. Significantly, we discovered that the adsorbed water in zeolite channels promoted the •OH-mediated oxidation reaction pathway, offering thermodynamic advantages over the conventional superoxide radical (•O2-)-dominated reaction pathway. The incorporation of Zn2+ into CABB@ZSM-5 further boosted benzaldehyde production by 2-fold. This work redefines the role of zeolites, transforming them from passive supports into multifunctional scaffolds with significant potential in advanced photochemical applications.
Gao et al. (2025) studied this question.