Double Bonuses Achieved in Single-Atom Catalysts for Efficient Oxygen Evolution: Enhanced Reaction Kinetics and Reinforced Electrochemical Reconstruction

Single metal atoms decorated on earth-abundant transition-metal-based supports have attracted intensive attention toward oxygen evolution reaction (OER) due to their decent activity and low cost. However, further optimizing the catalytic performance is severely plagued by the limited active sites. Conventional optimization relies primarily on increasing the metal loading but is extremely difficult. Thus, it is imperative to go beyond the current design paradigms. Herein, it is reported that the anchored highly active single metal atoms can reinforce the electrochemical reconstruction of the supports and thus yield more substrate active sites. Consequently, increased amount of active sites and enhanced intrinsic activity can be readily realized simultaneously. Taking Ni2P4O12 decorated with single Ir atoms as a typical example, an extraordinary activity of eta 10 = 186 mV and eta 100 = 238 mV and robust stability up to 108 h are achieved. Mechanistic study uncovers that the reinforced reconstruction of Ni2P4O12 originates from the promoted PO43- leaching by single Ir atoms, which is an intrinsic feature of the supports to achieve such reinforcement. The proposed concept, decorating single metal atoms on supports featured by facile anion leaching, opens a new avenue to the design of practical electrocatalysts for efficient OER. Single Ir atoms decoration on Ni2P4O12 could enhance the intrinsic activity and reinforce the electrochemical reconstruction of the support to generate more active sites simultaneously. Comparison with Ir/NiO indicates the crucial role of supports with facile anion leaching in reinforcing electrochemical reconstruction. The Ir/Ni2P4O12 catalyst exhibits an extraordinary activity and robust stability for the oxygen evolution reaction.image