Temperature-Induced Structure Reconstruction to Prepare a Thermally Stable Single-Atom Platinum Catalyst

摘要

Single-atom noble metals on a catalyst support tend to migrate and agglomerate into nanoparticles owing to high surface free energy at elevated temperatures. Temperature-induced structure reconstruction of a support can firmly anchor single-atom Pt species to adapt to a high-temperature environment. We used Mn3O4 as a restructurable support to load single-atom Pt and further turned into single-atom Pt-on-Mn2O3 catalyst via high-temperature treatment, which is extremely stable under calcination conditions of 800 degrees C for 5 days in humid air. High-valence Pt4+ with more covalent bonds on Mn2O3 are essential for anchoring isolated Pt atoms by strong interaction. An optimized catalyst formed by moderate H2O2 etching exhibits the best performance and excellent thermal stability of single-atom Pt in high-temperature CH4 oxidation on account of more exposed Pt atoms and strong Pt-Mn2O3 interaction.