Mass production of thermally stable Pt single-atom catalysts for the catalytic oxidation of sulfur dioxide

Abstract

Owing to the 100% atom utilization and the potential in bridging the gap between homogeneous catalysis and heterogeneous catalysis, single-atom catalysts (SACs) have doubtlessly obtained broad attention from both academia and industry. However, the thermal stability and the simple and scalable production of single-atom catalysts remain an arduous project for their applications from laboratory curiosity to a practical solution of industrial chemical processes. Here, we report the synthesis of Pt SACs from commercial PtO₂ powders by calcining a physical mixture of PtO₂ aggregates with α-Fe₂O₃ or Fe-containing supports at high temperature. The thorough dispersion of PtO₂ powders into isolated Pt single atoms is attributed to the anti-Ostwald ripening process promoted by a strong covalent metal–support interaction between Pt and Fe via high-temperature calcination. The as-prepared pellet Pt SACs were tested for the catalytic oxidation of sulfur dioxide, a key process unit in sulphuric acid production and environmental protection, and demonstrated good catalytic activity and excellent thermal stability.