Multi-amino strategy to enhance the formation of highly active Cu sites in zeolite for improved reaction

Metal-zeolite catalysts are widely utilized in various industrial reactions. However, the size, loading, and reduction of metal species are interdependent, complicating efforts to optimize their catalytic performance. In this study, we introduce a novel strategy for the synthesis of metal-zeolite catalysts, termed the multi-amino effect. This new method involves functionalizing zeolite surfaces with aliphatic diamines, such as 1,3-diaminopropane, to leverage the multifaceted properties of the amino group. 1,3-diaminopropane is anchored to the zeolite framework via one terminal amino group, while the other terminal amino group facilitates the efficient loading and dispersion of Cu species through interaction with Cu 2+ . The multi-amino groups present in the structure enable the in situ multi-stage release of abundant NH 3 during calcination, facilitating the self-reduction of Cu species to generate a high proportion of Cu + and Cu 0 species. Notably, the Cu-MOR catalyst prepared by this approach exhibits a significantly improved methyl acetate production rate, which is 1.56 times higher than that of the traditional hydrogen reduction method and 1.37 times greater than that of the ammonia pool method, owing to the abundance of highly dispersed and highly active Cu sites (Cu + :Cu 0  ≈ 1:1). This multi-amino effect strategy will help to develop more efficient and tunable metal-zeolite catalysts, driving advances in industrial processes such as sustainable chemical production and energy conversion, with significant improvements in both catalytic activity and cost-effectiveness.