Amino-Doping Regulates the Surface of Nickel-Based Catalysts to Promote the Formation of the Real Active States

Abstract

The generation of the real active states (NiOOH) on the nickel-based catalysts’ surface is a crucial step for anodic oxidation reactions. However, achieving a sufficient number of active states on nickel-based electrocatalysts surface remains a significant challenge. In this study, we propose an effective surface modification strategy using N-contained species to regulate the surface of nickel-based catalysts, and successfully construct a stable and efficient bifunctional electrocatalyst namely, N-doped-Ni(OH)2/NF (noted as NDN/NF). The NDN/NF catalyst shows an outstanding performance, with a current density of 10 mA cm-2 achievable at a voltage of only 1.35 V (vs. RHE) in ethanol oxidation reaction (EOR), outperforming most nickel-based catalysts. The catalyst also exhibits exceptional stability with a constant overpotential during the 20 h chronopotentiometry (CP) tests. The formation of active states is promoted by the shortened Ni-O bond resulting from the coordination deficiency of nickel, as confirmed by density functional theory (DFT) calculations.

Keywords: nickel-based catalyst, EOR, hydrogen generation, amino-doping, active states generation