Built-In Electric Field in Charge-Intercalated Catalysts: Excessive Electron Migration Stabilizes Zinc Active Sites for Propane Dehydrogenation

Propane dehydrogenation (PDH) to propylene is constrained by the trade-off between catalyst activity, selectivity, and stability, especially for non-precious metals. Herein, a ZnAl-layered double oxide/montmorillonite (ZnAl-LDO/MMT) heterojunction catalyst is designed via interfacial electrostatic self-assembly. A built-in electric field (BIEF) is constructed at the heterointerface, which drives directional electron transfer. This unique configuration effectively inhibits the over-reduction of Zn 2+ to volatile Zn 0 , thereby stabilizing the active centers. The optimal catalyst delivers a propane conversion of 69.61% with a propylene selectivity of 88.5% at 575°C, achieving a propylene space-time yield (2.06 mmol·g −1 ·h −1 , normalized to the active component) that is ten times higher than that of the ZnAl-LDO reference. Remarkably, it maintains stable performance over 55 reaction-regeneration cycles. In situ characterizations, combined with density functional theory (DFT), reveal that the enhanced performance is consistent with the computational result of a 0.97 eV upshift in the d-band center of ZnAl-LDO upon compositing with MMT, which strengthens propane adsorption. In situ FT-IR and Raman results suggest that interfacial engineering via the BIEF, likely promotes the formation of specific Zn─O X ─Si active sites, thereby selectively producing propylene while suppressing CO 2 formation at 300°C. This work reports a BIEF engineering strategy for designing non-precious metal PDH catalysts, which demonstrates enhanced activity and stability.