Remote Polyoxometalates Modulated the d/p-Band Center Proximity in Vanadia-Based Catalyst for Simultaneous Elimination of NO_<i>x</i> and Chlorobenzene

Modulating vanadia-based metal oxides via dopants has been extensively exploited for the development of highly efficient catalysts for multipollutant control (MPC). While high-performance simultaneous elimination has been achieved through the pillar effect of active vanadia (VOx) species, a comprehensive understanding of the atomic orbital variations attracted by dopants remains insufficient. Herein, vanadia supported on polyoxometalates-titania catalysts via hydroxy anchoring are designed to reduce the competitive adsorption of multiple pollutants and promote the generation of inorganic chlorine species for MPC. The polyoxometalate-modified catalysts exhibit outstanding conversions of CB and NOx, with turnover frequency values approximately 59.83 and 3.37 times higher than the original sample, respectively. This study demonstrates MPC catalysis facilitated by a remote polyoxometalate-induced electronic interaction via a distant arrangement of isolated V clusters and Keggin-type polyoxometalates supported on the TiO2 surface. Polyoxometalates enhance the V 3d orbital occupancy, boost the proximity between the d/p-band centers of vanadia, and significantly break the C–Cl bond under NH3 preadsorption. Especially, the generation of nitrate–ester by interacting with monodentate nitrate and adsorbed carboxylate could accelerate the deep oxidation of multipollutants. This study offers a promising approach for low-loading vanadium SCR catalysts, enabling highly efficient MPC under low-temperature conditions.