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Plasma Pretreatment of Pt Single-Atom Precursors Supported on Mechanically Activated Al 2 O 3 : Enhanced Performance in Propane Dehydrogenation

Year: 2025

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide We investigated the effect of catalyst pretreatment with “cold” plasmas on the catalytic performance of Pt single-atom catalyst (SAC) precursors supported on Al 2 O 3 for the propane dehydrogenation reaction. We found that the catalysts treated with a hydrogen plasma before the conventional calcination/reduction steps showed considerably increased propane conversion without loss of selectivity, whereas exposure to an argon plasma did not result in such an effect. Moreover, the H 2 plasma-treated catalyst showed a lower deactivation rate, suggesting better long-term stability. The structural and chemical evolution of the catalysts studied by TEM, XAS, XPS, and DRIFTS showed that the H 2 plasma: (i) partially reduces singly dispersed Pt 2+ species and promotes Pt clustering; (ii) decreases the amount of Cl remaining after the use of the hexachloroplatinic acid precursor; and (iii) enhances surface defects in the alumina support. We propose that the promotional effect of the H 2 plasma lies in the specific modification of the alumina surface, which in turn alters the metal-support interaction and leads to the formation of a more active Pt/Al 2 O 3 interface during the subsequent oxidation and reduction steps. The results show that nonthermal plasma treatments of single-atom precursors can become a tool for tuning the catalytic performance of highly dispersed metal catalysts.

Source: Journal of the American Chemical Society

DOI: 10.1021/jacs.5c12230