Hole‐Activated Lattice Oxygen Enables Pt‐Free Propane Dehydrogenation by Eliminating the Hydrogen Recombination Bottleneck

Abstract

ABSTRACT Gallia–alumina (Ga x Al 2− x O 3 ) enables efficient propane dehydrogenation (PDH) via C–H activation at Ga–O pairs, but the overall rate is limited by sluggish hydrogen recombination to H 2 . Although Pt promotion alleviates this bottleneck, it introduces drawbacks including precious‐metal cost and regeneration‐induced sintering. Here, we show that Mg doping into Ga x Al 2− x O 3 electronically activates lattice oxygen to enable rapid H 2 evolution directly on the oxide, eliminating the need for Pt promotion. Electron paramagnetic resonance spectroscopy reveals the formation of hole‐type oxygen species upon Mg incorporation, while kinetic/isotopic measurements and theoretical calculations demonstrate substantially accelerated hydrogen recombination kinetics. In situ infrared spectroscopy further shows rapid depletion of surface hydrogen species, consistent with facilitated H 2 formation from Ga–H and O–H intermediates. At 853 K, Mg‐doped Ga x Al 2− x O 3 exhibits a threefold higher propylene formation rate than the undoped material at 97% propylene selectivity, outperforming benchmark PtSn/ γ ‐Al 2 O 3 and CrO x / γ ‐Al 2 O 3 catalysts. Furthermore, the fully oxide‐based catalyst shows the slowest deactivation over 30 dehydrogenation–regeneration cycles. These findings establish lattice‐oxygen electronic engineering as a practical strategy for achieving both high activity and exceptional regeneration stability in oxide‐catalyzed dehydrogenation chemistry.