Related Experiment Video
Updated: Jun 29, 2025
Synthesis and Performance Characterizations of Transition Metal Single Atom Catalyst for Electrochemical CO2 Reduction
Published on: April 10, 2018
Glycerol Electrolyzer with Graphite Anode and Cathode Produces Carbonyl Compounds and Hydrogen: Background
Nicolly C Yonamine1, Cinthia R Zanata1, Matheus B C de Souza2,3
1Institute of Physics, Federal University of Mato Grosso do Sul, Campo Grande 79070-900, Brazil.
Abstract:
This study unveils a novel role of bare graphite as a catalyst in glycerol electrooxidation and hydrogen evolution reactions, challenging the prevailing notion that current collectors employed in electrolyzers are inert. Half-cell experiments elucidate the feasibility of glycerol oxidation and hydrogen production on bulk graphite electrodes at potentials exceeding 1.7 V. The investigation of varying glycerol concentrations (0.05 to 1.5 mol L-1) highlights a concentration-dependent competition between glycerol electrooxidation and oxygen evolution reactions. Employing an H-type glycerol electrolyzer, polarization curves reveal significant activation polarization attributed to the low electroactivity of the anode. Glycerol electrolysis at different concentrations yields diverse product mixtures, including formate, glycolate, glycerate, and lactate at the anode, with concurrent hydrogen generation at the cathode. The anolyte composition changes with glycerol concentration, resulting in less-oxidized compounds at higher concentrations and more oxidized compounds at lower concentrations. The cell voltage also influences the product formation selectivity, with an increased voltage favoring more oxidized compounds. The glycerol concentration also affects hydrogen production, with lower concentrations yielding higher hydrogen amounts, peaking at 3.5 V for 0.05 mol L-1. This model quantitatively illustrates graphite's contribution to current and product generation in glycerol electrolyzers, emphasizing the significance of background current and products originating from current collectors if in contact with the reactants. These results have an impact on the efficiency of the electrolyzer and raise questions regarding possible extra non-noble "nonparticipating" current collectors that could affect overall performance. This research expands our understanding of electrocatalysis on graphite surfaces with potential applications in optimizing electrolyzer configurations for enhanced efficiency and product selectivity.
More Related Videos
06:39Author Spotlight: Design and Evaluation of Au-Electroplated Carbon Fiber Cloth Electrodes for Hydrogen Peroxide Fuel Cells
Published on: October 20, 2023
06:32A Simple, Low-cost, and Robust System to Measure the Volume of Hydrogen Evolved by Chemical Reactions with Aqueous Solutions
Published on: August 17, 2016
Related Concept Videos
03:00Electrolysis
01:20Aldehydes and Ketones with Water: Hydrate Formation
The formation of hydrates is a reversible reaction. Hydrate formation is influenced by steric and electronic factors accompanying the alkyl substituents on the carbonyl group: The rate of hydrate formation increases with a decrease in the number of alkyl groups attached to the carbonyl carbon. Hence,...
01:13Esters to Carboxylic Acids: Acid-Catalyzed Hydrolysis
During hydrolysis, the ester is first activated towards nucleophilic attack through the protonation of the carboxyl oxygen atom by the acid catalyst. The protonation makes the ester carbonyl carbon more electrophilic. In the next step, water acts as a nucleophile and adds to the...
02:23Alcohols from Carbonyl Compounds: Reduction
Catalytic hydrogenation is similar to the reduction of an alkene or alkyne by adding H2 across the pi bond in the presence of transition metal catalysts like Raney Ni, Pd–C, Pt, or Ru. Aldehydes and ketones can be reduced by this method, often under mild to moderate heat (25–100°C) and...
00:43Dehydration of Aldols to Enones: Acid-Catalyzed Aldol Condensation
03:12Batteries and Fuel Cells