Efficient preparation of CuCe-SAPO-34 catalyst and its NH3-SCR performance

Excessive levels of NO_x in the atmosphere can cause various environmental issues, including acid rain, ozone layer depletion, and photochemical smog—conditions that pose serious risks to human health. As a result, reducing NO_x emissions from vehicle exhaust is an urgent global challenge that demands attention. Ammonia selective catalytic reduction (NH₃-SCR) technology is widely used for exhaust gas treatment because of its high denitrification efficiency and stability. The effectiveness of NH₃-SCR largely depends on the catalyst employed. Among the available catalysts, Cu-SSZ-13 zeolites have shown exceptional promise due to their high NO_x conversion rates, N₂ selectivity, and hydrothermal stability. However, the high cost of the templates used in Cu-SSZ-13 makes Cu-SAPO-34 which has the same CHA structure with Cu-SSZ-13 a more economically viable option for commercial use. To further improve both the denitrification performance and hydrothermal stability of Cu-SAPO-34 catalysts, this study introduces Cerium, a rare-earth metal, to modify the Cu-SAPO-34 catalyst for NH₃-SCR applications. The experimental results show that the incorporation of Ce significantly enhances the catalytic performance, particularly at low temperatures, while also improving the low-temperature hydrothermal stability of CuCe-SAPO-34. Characterization analysis reveals that the introduction of Ce increases the number of acid sites and facilitates the redox cycling process, both of which contribute to the enhanced catalytic activity. These findings underscore the crucial role of Ce in optimizing the performance of CuCe-SAPO-34 catalysts, making them a promising candidate for more efficient and cost-effective NO_x reduction in vehicle exhaust treatment.