Zeolite Confinement and Defect Engineering Steering the Photocatalytic Conversion of CO 2 to C 2 H 4

Abstract

The photocatalytic reduction of carbon dioxide (CO 2 ) into high-valueadded chemicals represents a promising strategy to address the energy crisis and global warming. Among various reduction products, the selective generation of ethylene (C 2 H 4 ) remains particularly challenging. In this study, Ag and Cu x O nanoparticle comodified zeolite TS-1 (Ag-Cu x O/TS-1) were successfully synthesized via a combined ion exchange and in-situ reduction approach. Under simulated solar light irradiation, the optimized Ag-Cu x O/TS-1 catalyst achieves efficient CO 2 -to-C 2 H 4 conversion, yielding a remarkable C 2 H 4 production rate of 2.02 μmol•g -1 •h -1 with 100% selectivity toward C 2 H 4 . The remarkable activity and selectivity originate from the synergistic effect of the zeolite confinement effect, abundant oxygen vacancies, and stable Cu⁺ species, which collectively enhance visible-light absorption, promote the separation of photogenerated charge, and facilitate enrichment of *CO and C-C coupling, as proven by in-situ Ranman. Moreover, the catalyst demonstrates excellent recyclability, maintaining over 80% of its initial activity after four consecutive reaction cycles. This work highlights the potential of coupling plasmonic metals with zeolite-based confinement environments and defect engineering, providing a feasible strategy for the efficient and selective conversion of CO 2 into value-added C 2 products.