Changes in the oxidation state of Pt single-atom catalysts upon removal of chloride ligands and their effect for electrochemical reactions

Single atomic Pt supported on TiC was prepared from chloride Pt precursors, then the chloride ligands were intentionally removed by increasing the reduction temperature. The 0.2 wt% Pt/TiC catalyst reduced at 300 °C had more reduced Pt single-atoms with fewer chloride ligands and exhibited the highest currents for H2O2 formation in the electrochemical oxygen reduction reaction. Controlling the oxidation state of the single-atoms is very important to maximize the activity of the single-atom catalysts.