Insight into Key Parameters for Fabricating Stable Single-Atom Pt-Nix Alloy by Reduction Environment-Induced Anti-Ostwald Effects

Abstract

Developing single-atom catalysts with superior stability under reduction conditions is essential for hydrogenation/dehydrogenation catalysis and green hydrogen generation. In this contribution, single-atom Pt catalysts were achieved via a reduction environment-induced anti-Ostwald approach in the highly confined Ni species (Pt-Ni_x ) on nonreducible Al₂ O₃ matrix. In-situ X-ray absorption spectroscopy indicated that the isolated Pt-Ni_x metallic bonds, generated at high reduction temperature, dominated the formation of single Pt atoms. A relatively large cluster of metallic Ni would benefit the stabilization of Pt single atom as observed via high-angle annular dark-field scanning transmission electron microscopy and validated by density functional theory simulation. Excellent performance on cellulose hydrogenolysis was demonstrated under harsh reductive and hydrothermal conditions, potentially expandable to other hydrogen involved reactions like CO₂ hydrogenation, green hydrogen production from different hydrogen carriers, and beyond.

Keywords: X-ray absorption; cellulose; hydrogenolysis; nanocatalysts; platinum.