Title: Stable anchoring of single rhodium atoms by indium in zeolite alkane dehydrogenation catalysts
Article Link: https://www.science.org/doi/abs/10.1126/science.adk5195
言之成理推送：https://mp.weixin.qq.com/s/K0FfyI3gs0d-gzlhZ5mHHA
Maintaining the stability of single-atom catalysts in high-temperature reactions remains extremely challenging because of the migration of metal atoms under these conditions. We present a strategy for designing stable single-atom catalysts by harnessing a second metal to anchor the noble metal atom inside zeolite channels. A single-atom rhodium-indium cluster catalyst is formed inside zeolite silicalite-1 through in situ migration of indium during alkane dehydrogenation. This catalyst demonstrates exceptional stability against coke formation for 5500 hours in continuous pure propane dehydrogenation with 99% propylene selectivity and propane conversions close to the thermodynamic equilibrium value at 550°C. Our catalyst also operated stably at 600°C, offering propane conversions of >60% and propylene selectivity of >95%.
Our studies revealed that In species function like solvents and alloying agents, which effectively created in situ dilute Rh atoms in the form ofRhIn4 sites attached onto the zeolite framework through In–O linkages. This transformation turned the unselective and unstable Rh-based catalysts into highly selective and ultrastable PDH catalysts. Our findings also offer a simple protocol for synthesizing robust single-atom catalysts that are operated at harsh reaction conditions.
