Tailoring the Local Environment of Platinum in Single‐Atom Pt1/CeO2 Catalysts for Robust Low‐Temperature CO Oxidation

A single‐atom Pt1/CeO2 catalyst formed by atom trapping (AT, 800 °C in air) shows excellent thermal stability but is inactive for CO oxidation at low temperatures owing to over‐stabilization of Pt2+ in a highly symmetric square‐planar Pt1O4 coordination environment. Reductive activation to form Pt nanoparticles (NPs) results in enhanced activity; however, the NPs are easily oxidized, leading to drastic activity loss. Herein we show that tailoring the local environment of isolated Pt2+ by thermal‐shock (TS) synthesis leads to a highly active and thermally stable Pt1/CeO2 catalyst. Ultrafast shockwaves (>1200 °C) in an inert atmosphere induced surface reconstruction of CeO2 to generate Pt single atoms in an asymmetric Pt1O4 configuration. Owing to this unique coordination, Pt1δ+ in a partially reduced state dynamically evolves during CO oxidation, resulting in exceptional low‐temperature performance. CO oxidation reactivity on the Pt1/CeO2_TS catalyst was retained under oxidizing conditions. A highly active and robust single‐atom Pt1/CeO2 catalyst was developed for CO oxidation by tailoring the local environment of isolated Pt2+ through thermal‐shock synthesis (see picture). Ultrafast shockwaves in an inert atmosphere generated Pt single atoms in an asymmetric Pt1O4 configuration, resulting in greatly enhanced low‐temperature activity that was retained under oxidizing conditions.