Entropy‐Stabilized Aluminate Catalysts That Break the Activity–Stability Tradeoff in CF ₄ Hydrolysis

Abstract

ABSTRACT Tetrafluoromethane (CF 4 ) 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 ‐Al 2 O 3 . 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 H 2 O 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 AlF 3 formation and its subsequent hydrolysis to α ‐Al 2 O 3 . Mechanistic studies further establish that CF 4 hydrolysis proceeds via a Mars–van Krevelen‐type pathway in which lattice oxygen first oxidizes CF x surface intermediates and is replenished by H 2 O. These findings identify entropy‐stabilized aluminates as a robust materials platform capable of simultaneously achieving high activity and long‐term durability for CF 4 hydrolysis.