Atomically Dispersed Pt-Triggered CZO/Cu-SSZ-13 Coupling Catalyst for the Efficient Low-Temperature Selective Catalytic Reduction of NO_x

In this study, an atomically dispersed Pt-loaded Ce_0.6Zr_0.4O₂/Cu-SSZ-13 (Pt-CZO/Cu-SSZ-13) coupling catalyst was fabricated by a facile grinding strategy, and its structure and catalytic performance for the selective catalytic reduction (SCR) of NO_x by NH₃ were systematically investigated. The results reveal that the resulting Pt-CZO/Cu-SSZ-13 shows outstanding catalytic activity, achieving almost complete conversion of NO_x at 145 °C, notably lower as compared with that of Cu-SSZ-13 with approximately 100% NO_x conversion at 200 °C. The reason should be originated from the coexistence of Pt species in both single-atom and nanocluster forms, which not only significantly enhance the reactivity of lattice oxygen in CZO but also considerably increase the number of Brønsted acid sites. Both of these factors coordinately aid the adsorption and thereafter the activation of NO_x and NH₃, and then promote the NH₃–SCR activity of the Pt-CZO/Cu-SSZ-13 coupling sample noticeably at the low-temperature range. This study introduces a viable approach to address the pressing issue of NO_x emissions during the idle and cold-start phases of diesel engines.