Introducing hydroxyl groups to tailor the d-band center of Ir atom through side anchoring for boosted ORR and HER

Abstract

Tuning the coordination atoms of central metal is an effective means to improve the electrocatalytic activity of atomic catalysts. Herein, iridium (Ir) is proposed to be asymmetrically anchored by sp-N and pyridinic N of hydrogen-substituted graphdiyne (HsGDY), and coordinated with OH as an Ir atomic catalyst (Ir1-N-HsGDY). The electron structures, especially the d-band center of Ir atom, are optimized by these specific coordination atoms. Thus, the as-synthesized Ir1-N-HsGDY exhibits excellent electrocatalytic performances for oxygen reduction and hydrogen evolution reactions in both acidic and alkaline media. Benefiting from the unique structure of HsGDY, IrN2(OH)3 has been developed and demonstrated to act as the active site in these electrochemical reactions. All those indicate the fresh role of the sp-N in graphdiyne in producing a new anchor way and contributing to promote the electrocatalytic activity, showing a new strategy to design novel electrochemical catalysts.