Covalent attachment of [Ni(alkynyl-cyclam)]2+ catalysts to glassy carbon electrodes

Abstract

Surface modification of glassy carbon electrodes (GCEs) with molecular electrocatalysts is an important step towards developing more efficient heterogeneous CO₂ reduction materials. Here, we report direct anodic electrografting of [Ni(alkynyl-cyclam)]²⁺ catalysts to the surface of GCEs in one simple step using inexpensive earth-abundant chemicals. When modified, these electrodes show reversible electrochemistry in organic solvents with zero peak-to-peak separations (ΔE = 0) and non-diffusive I (V) profiles that are typical for heterogeneous redox materials. CPE of these electrodes showed enhanced formation of H₂ gas relative to CO compared to homogeneous catalysts.