Electrocatalytic Hydrogen Evolution by Water‐Soluble Cobalt (II), Copper (II) and Iron (III) meso‐Tetrakis(carboxyl)porphyrin

Abstract Three water‐soluble carboxyl metalloporphyrins, cobalt (II), copper (II) and iron (III) meso ‐tetrakis (carboxyl) porphyrin were prepared and applied as homogeneous electrocatalysts for hydrogen evolution reaction (HER) with acetic acid, trifluoroacetic acid, p ‐toluene sulfonic acid and water as proton sources. Cyclic voltammetry (CV) results revealed the HER underwent different routes for these metalloporphyrins. Electrocatalysis tests in buffer solution of pH=7.0 showed the TOFs of cobalt (II), copper (II) and iron (III) meso ‐tetrakis (carboxyl) porphyrin were 184.78, 160.28 and 184.87 mol −1 ⋅ h −1 and the faradaic efficiency were 94.37 %, 93.01 % and 96.98 % at an overpotential of 788 mV, respectively. These results indicate the synthesized metal carboxyl porphyrins have good electrocatalytic activity for HER.