General synthesis for supported single-atom catalysts using hydroxyl nests in zeolites

Due to their well-defined geometric and electronic structures and fully exposed active sites, single-atom catalysts (SACs) exhibit significantly enhanced catalytic activity in the field of catalysis. However, the controllable synthesis of SACs, particularly in a simple and scalable manner, presents formidable challenges. Here, we report the general synthesis of SACs containing Co, Ni, Cu, and Zn using a direct impregnation method. Atomically dispersed transition metal atoms over zeolite supports are confirmed by integrated differential phase contrast scanning transmission electron microscopy (iDPC-STEM) and extended X-ray absorption fine structure (EXAFS) spectroscopy. Detailed studies reveal that the dispersion process originates from the trapping of metal atoms by silane nests. Notably, the Co-SAC catalyst demonstrated superior catalytic performance in the industrially significant propane dehydrogenation reaction. This synthetic strategy is straightforward and amenable to large-scale production of thermally stable SACs for industrial applications. A general method for synthesizing single-atom catalysts (SACs) has been developed using direct impregnation, leveraging the internal silanol structure of molecular sieves to trap metal species.