Non‐Classical Deactivation Mechanism in a Supported Intermetallic Catalyst for Propane Dehydrogenation

Abstract Platinum‐based supported intermetallic alloys (IMAs) demonstrate exceptional performance in catalytic propane dehydrogenation (PDH) primarily because of their remarkable resistance to coke formation. However, these IMAs still encounter a significant hurdle in the form of catalyst deactivation. Understanding the complex deactivation mechanism of supported IMAs, which goes beyond conventional coke deposition, requires meticulous microscopic structural elucidation. In this study, we unravel a nonclassical deactivation mechanism over a PtZn/γ‐Al 2 O 3 PDH catalyst, dictated by the PtZn to Pt 3 Zn nanophase transformation accompanied with dezincification. The physical origin lies in the metal support interaction (MSI) that enables strong chemical bonding between hydroxyl groups on the support and Zn sites on the PtZn phase to selectively remove Zn species followed by the reconstruction towards Pt 3 Zn phase. Building on these insights, we have devised a solution to circumvent the deactivation by passivating the MSI through surface modification of γ‐Al 2 O 3 support. By exchanging protons of hydroxyl groups with potassium ions (K) on the γ‐Al 2 O 3 support, such a strategy significantly minimizes the dezincification of PtZn IMA via diminished metal‐support bonding, which dramatically reduces the deactivation rate from 0.2044 to 0.0587 h −1 . These findings decode the nonclassical PDH deactivation mechanism over supported IMA catalysts and elaborate a new logic for the design of high‐performance IMA based PDH catalysts with long‐term stability.