Electrochemical Conversion of Alcohols into Acidic Commodities on Nickel Sulfide Nanoparticles

Abstract

The electrocatalytic oxidation of alcohols is a potentially cost-effective strategy for the synthesis of valuable chemicals at the anode while simultaneously generating hydrogen at the cathode. For this approach to become commercially viable, high-activity, low-cost, and stable catalysts need to be developed. Herein, we demonstrate an electrocatalyst based on earth-abundant nickel and sulfur elements. Experimental investigations reveal the produced NiS displays excellent electrocatalytic performance associated with a higher electrochemical surface area (ECSA) and the presence of sulfate ions on the formed NiOOH surface in basic media. The current densities reached for the oxidation of ethanol and methanol at 1.6 V vs reversible hydrogen electrode (RHE) are up to 175.5 and 145.1 mA cm −2 , respectively. At these high current densities, the Faradaic efficiency of methanol to formate conversion is 98% and that of ethanol to acetate is 81%. Density functional theory calculations demonstrate the presence of the generated sulfate groups to modify the electronic properties of the NiOOH surface, improving electroconductivity and electron transfer. Besides, calculations are used to determine the reaction energy barriers, revealing the dehydrogenation of ethoxy groups to be more favorable than that of methoxy on the catalyst surface, which explains the highest current densities obtained for ethanol oxidation.

Boosting Hydrogen Evolution by Methanol Oxidation Reaction on Ni-Based Electrocatalysts: From Fundamental Electrochemistry to Perspectives

“…125 Other studies suggest that the second nonmetal did not change the methanol-to-formate FE during the electrocatalytic MOR process. 46,128 These studies provide additional insights into modulating the active-center coordination environment via oxyanions for organic molecule transformation.…”

“…(c) Calculated reaction pathways for the conversion of methanol to formate on NiOOH(001) are detailed with the free energy of each configuration being provided in electron volts. Reprinted from ref . Copyright 2022 American Chemical Society.…”

Enhanced Electrochemical Hydrogenation of Benzaldehyde to Benzyl Alcohol on Pd@Ni-MOF by Modifying the Adsorption Configuration

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