Single‐Atom La Promoter Breaks the Activity–Stability Trade‐Off on Al 2 O 3 ‐Supported Pt Catalysts for Propane Dehydrogenation

ABSTRACT Achieving acceptable propane conversion in the endothermic propane dehydrogenation (PDH) reaction demands high temperatures, which exacerbate the activity‐stability trade‐off through low propylene selectivity and accelerated coking deactivation. Addressing this, we leverage the essence of Le Chatelier's principle—shifting reaction equilibrium through rapid in situ H 2 removal—a strategy conventionally deemed unattainable on Al 2 O 3 supports due to hydrogen spillover limitations. The synergistic sites between the La 1– SnO x promoter and Pt enable the redistribution of surface H species away from the Pt active centers. Consequently, the La 1 ‐Pt n /SnO x /Al 2 O 3 catalyst achieves propane conversions approaching the thermodynamic equilibrium conversion over 300–600 °C. Moreover, modulation of hydrogen surface diffusion behavior influences unselective C–C(H) scission of propylene and modifies coke structure and secondary cracking propensity, which is associated with the substantially improved durability observed for La 1 ‐Pt n /SnO x /Al 2 O 3 compared to the Pt n /SnO x /Al 2 O 3 (commercial mimic) catalyst. This superior performance demonstrates that, the introduction of La 1 –SnO x not only overcomes the inert hydrogen‐trapping nature of Al 2 O 3 , but also alleviates the conventional activity–stability trade‐off in PDH catalysis, illustrating how atomically dispersed promoters can circumvent intrinsic support limitations and thereby expand the performance boundaries of Al 2 O 3 ‐based dehydrogenation catalysts.