Sub-nanometer Pt2In3 intermetallics as ultra-stable catalyst for propane dehydrogenation

Pt-based catalysts are the typical industrial catalysts for propane dehydrogenation (PDH), which still suffer from insufficient long-term durability due to the structural instability and coke deposition. A commercial γ-Al2O3 supported thermally robust sub-nanometer Pt2In3 intermetallic catalyst with atomically ordered structure and rigorously separated Pt single atoms was fabricated, which showed outstanding robustness in 240 h long-term operation at 600 °C with the deactivation rate constant kd as low as 0.00078 h−1, ranking among the lowest reported values. Based on various in situ characterizations and theoretical calculations, it was proved that the catalyst stability not only resulted from the separated Pt single-atom sites but also significantly affected by the distance of adjacent Pt atoms. An increasing distance to 3.25 Å in the Pt2In3 could induce a weak π-adsorption configuration of propylene on Pt sites, which facilitated the desorption of propylene and restrained the side reactions like coking.