Synergistically enhanced ORR and HER performance on Co-N-C coupled in-situ generated PtCo intermetallic

Integrating multi-scale sites in a composite catalyst is vital to realize efficient electrocatalysis.Herein,a synergistic composite catalyst consisting of Co atomic sites and in-situ generated PtCo intermetallic compounds （IMCs）(o-PtCo@CoNC) is proposed through Co pre-anchoring and subsequent impregnation-reduction method.High loading of Co atoms provides a chance for in-situ generating PtCo ordered intermetallic compounds.The remaining Co single atoms and PtCo IMCs construct synergistic electrocatalytic micro-regions.Benefiting from the ordered structure,synergistic effect of Pt Co IMCs and Co single atoms,o-PtCo@CoNC exhibits excellent electrocatalytic performance for oxygen reduction reaction （ORR） and hydrogen evolution reaction （HER） with mass activity of 1.21 A mgPt-1（at 0.9 V） and5.70 A mgPt-1（at an overpotential of 100 mV）,respectively.Besides,o-PtCo@CoNC delivers negligible loss of half-wave potential and overpotential during long-term stability test in acid solutions,with 13 mV decay after 50,000 potential cycles for ORR and a 2.7 mV decay after 20,000 potential cycles for HER.The integration strategy of single-atomic sites coupled IMCs paves the way for enhancing the activity and durability of Pt-based electrocatalysts.