Low carbon alcohol fuel electrolysis of hydrogen generation catalyzed by a novel and effective Pt–CoTe/C bifunctional catalyst system

Abstract

Low carbon alcohol fuels electrolysis under ambient conditions is promising for green hydrogen generation instead of the traditional alcohol fuels steam reforming technique, and highly efficient bifunctional catalysts for membrane electrode fabrication are required to drive the electrolysis reactions. Herein, the efficient catalytic promotion effect of a novel catalyst promoter, CoTe, on Pt is demonstrated for low carbon alcohol fuels of methanol and ethanol electrolysis for hydrogen generation. Experimental and density functional theory calculation results indicate that the optimized electronic structure of Pt–CoTe/C resulting from the synergetic effect between Pt and CoTe further regulates the adsorption energies of CO and H∗ that enhances the catalytic ability for methanol and ethanol electrolysis. Moreover, the good water activation ability of CoTe and the strong electronic effect of Pt and CoTe increased the tolerance ability to the poisoning species as demonstrated by the CO-stripping technique. The high catalytic kinetics and stability, as well as the promotion effect, were also carefully discussed. Specifically, 71.9% and 75.5% of the initial peak current density was maintained after 1000 CV cycles in acid electrolyte for methanol and ethanol oxidation; and a low overpotential of 30 and 35 mV was required to drive the hydrogen evolution reaction in methanol and ethanol solution at the current density of 10 mA cm−2. In the two-electrode system for alcohol fuels electrolysis, using the optimal Pt–CoTe/C catalyst as bi-functional catalysts, the cell potential of 0.66 V (0.67 V) was required to achieve 10 mA cm−2 for methanol (ethanol) electrolysis, much smaller than that of water electrolysis (1.76 V). The current study offers a novel platform for hydrogen generation via low carbon alcohol fuel electrolysis, and the result is helpful to the catalysis mechanism understanding of Pt assisted by the novel promoter.