Synergistic catalytic removal of NOx and chlorobenzene by a combination punch of Lewis and Bronsted acid and redox sites.

Multi-pollutant control of nitrogen oxides (NOx) and chlorinated aromatics in industrial flue by synergistic catalysis is still a huge challenge. Tailoring well-defined interfacial structures of multi-component heterogeneous catalysts has become an effective strategy for facilitating reactions involving multiple reactants. Here, a coupling of copper and tin oxide with particle-particle heterostructure supported on H-ZSM5 is designed to achieve a high-performance catalyst for NOx and chlorobenzene synergistic elimination. Experimental and theoretical calculation (DFT) studies show that the particle-particle coupling Janus heterostructure induced Sn-O-Cu interfaces. The strong electronic interaction improves the interfacial charge redistribution and mediates the activated interfacial oxygen, supporting redox (R) sites for the redox reaction cycle. Together with the abundant intrinsic Lewis (L) acid sites from CuOx and Brønsted (B) acid sites from the H-ZSM-5 interface, a combination punch of ideal L-B-R sites was constructed for the synergistic catalysis of NOx reduction and chlorobenzene oxidation. The designed Sn-Cu/H-ZSM5 catalyst exhibits significant low-temperature synergistic catalytic activity, a wide temperature window, robust long-term stability, and excellent water resistance, which outperforms Sn/H-ZSM5 and Cu/H-ZSM5. Moreover, in situ infrared spectra of serial transient reactions evidenced that the NOx reduction reaction promotes chlorobenzene oxidation. This novel strategy of regulating the overall L acid, B acid, and redox properties to fabricate balanced L-B-R sites via interfacial engineering provides a distinct strategy for facilitating the synergistic abatement of NOx and chlorinated aromatics.