Effect of atomic-layer-deposited TiO2 on carbon-supported Ni catalysts for electrocatalytic glycerol oxidation in alkaline media

•Thin TiO2 layers were coated on Ni/C by atomic layer deposition.•The Ni surface oxidation state of Ni/C was changed by the TiO2 coating.•TiO2-coated Ni/C exhibited enhanced glycerol electrooxidation in alkaline medium.•DFT showed the effect of the oxidized Ni surface on glycerol adsorption.

Thin TiO2 layers were deposited onto a carbon-supported Ni catalyst (Ni/C) through atomic layer deposition (ALD) and the resulting TiO2-coated Ni/C (ALD(TiO2)-Ni/C) was utilized for electrochemical glycerol oxidation in alkaline media. X-ray photoelectron spectroscopy analysis demonstrated that the Ni surface phase of ALD(TiO2)-Ni/C mainly consisted of Ni(OH)2 while that of uncoated Ni/C was a mixed phase of NiO and Ni(OH)2. The ALD(TiO2)-Ni/C exhibited electrocatalytic activity at least 2.4 times higher than that of Ni/C. Density functional theory calculations were used to investigate how the modified Ni surface with the TiO2 coating affects the adsorption/desorption of glycerol.