Promoting Oxygen Evolution Reaction Induced by Synergetic Geometric and Electronic Effects of IrCo Thin-Film Electrocatalysts

초록

The advancement of water electrolysis technology has seeminglyplateaued. Further advances require new strategies to address the key limitations ofthe oxygen evolution reaction: high overpotential and low stability of electrodematerials. Herein, we designed a nanoporous Ir3Co-core@IrO2-shell electrocatalystwith 5 and 3 times higher mass activity and 6 and 2 times higher activity-stabilityfactors than conventional IrO2nanoparticles and Ir nanoporous electrocatalysts,respectively. The origin of the performance enhancement in the Ir3Co-core@IrO2-shell electrocatalyst was revealed in computational density functional theorycalculations. The residual Co after the dealloying process resulted in a down-shiftof thed-band center position, thus weakening the-OH*adsorption energy. Inaddition, the electronic conductivity was enhanced by the three-dimensionallyinterconnected structure. Under high-current-density operating conditions, theOhmic losses were reduced by the ultrafast charge transfer pathway provided by the metallic IrCo core

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