Entropy-Stabilized Aluminate Catalysts That Break the Activity-Stability Tradeoff in CF₄ Hydrolysis

Tetrafluoromethane (CF₄) is a potent, long-lived greenhouse gas widely used in semiconductor dry-etching processes, yet its abatement via hydrolysis remains challenging due to the lack of catalysts that simultaneously exhibit high activity and durability under strongly fluorinating, steam-rich conditions. Conventional alumina-based catalysts suffer from severe activity-stability tradeoffs, offering good activity only at the cost of rapid deactivation through surface-area loss, bulk fluorination, and the formation of catalytically inactive α-Al₂O₃. Here, we report an entropy-stabilized aluminate catalyst that overcomes this long-standing tradeoff by combining a multication aluminate framework with an entropy-stabilized lattice. The incorporation of multiple metal cations produces an electron-deficient Al-O environment that enhances heterolytic C-F bond activation while suppressing H₂O poisoning, thereby increasing intrinsic activity under practical conditions. Simultaneously, the lattice stabilization via high configurational entropy inhibits the propagation of fluorination into the bulk lattice, effectively suppressing in situ AlF₃ formation and its subsequent hydrolysis to α-Al₂O₃. Mechanistic studies further establish that CF₄ hydrolysis proceeds via a Mars-van Krevelen-type pathway in which lattice oxygen first oxidizes CF_x surface intermediates and is replenished by H₂O. These findings identify entropy-stabilized aluminates as a robust materials platform capable of simultaneously achieving high activity and long-term durability for CF₄ hydrolysis.