Electrochemical Production of Glycolic Acid from Oxalic Acid Using a Polymer Electrolyte Alcohol Electrosynthesis Cell Containing a Porous TiO2 Catalyst

Abstract

A liquid flow-type electrolyser that continuously produces an alcohol from a carboxylic acid was constructed by employing a polymer electrolyte, named a polymer electrolyte alcohol electrosynthesis cell (PEAEC). Glycolic acid (GC, an alcoholic compound) is generated on anatase TiO2 catalysts via four-electron reduction of oxalic acid (OX, a divalent carboxylic acid), accompanied with water oxidation, which achieves continuous electric power storage in easily stored GC. Porous anatase TiO2 directly grown on Ti mesh (TiO2/Ti-M) or Ti felt (TiO2/Ti-F) was newly fabricated as a cathode having favourable substrate diffusivity. A membrane-electrode assembly composed of the TiO2/Ti-M, Nafion 117, and an IrO2 supported on a gas-diffusion carbon electrode (IrO2/C) was applied to the PEAEC. We achieved a maximum energy conversion efficiency of 49.6% and a continuous 99.8% conversion of 1 M OX, which is an almost saturated aqueous solution at room temperature.

Integrating CO2 Capture with Electrochemical Conversion Using Amine-Based Capture Solvents as Electrolytes

“…After 5 h of electrolysis, three different products were detected in the liquid phase: formic, glycolic, and oxalates. While formate and oxalate are formed from direct conversion of CO 2 as depicted in eqs and , the formation of glycolate is a further reduction of the oxalate , according to eq . …”

Sustainable Electrochemical Production of Tartaric Acid

“…18,19 Chronoamperometry measurements were carried out at −1.0 and − 1.3 V using Ag and Pb electrodes, respectively, because at more negative potential TTA can be electrochemically reduced to malic acid. 15 The yield % and FE % related to the main liquid products detected by HPLC are shown in Figure 4.…”

“…Electrochemical synthesis is a potential candidate since TTA can be easily produced from the electrochemical reduction of glyoxylic acid (GLYA) , following the mechanism shown in Figure . GLYA is also a product from the electrochemical reduction of oxalic acid (OxA), a C 2 product from CO 2 reduction, which makes its production a sustainable process.…”

Zinc Battery Driven by an Electro-Organic Reactor Cathode

“…It is well-known that alcohols are safer energy carrier molecules and that consequently their production in batteries during electricity generation will be a distinct progress in the sustainable energy landscape. 56,57 The proposed Zn-fuel synthesizer battery consists of a Zn anode housed in 6 M KOH as the anodic half-cell and a Pb electrode dipped in 2 M H 2 SO 4 containing 0.7 M OA as the cathodic half-cell. The Pb electrode was chosen as the cathodic electrocatalyst because of its electrocatalytic ability to reduce OA to alcoholic compounds.…”

“…We further demonstrate that the proposed Zn-organic reactor battery can be utilized for fuel synthesis, and we establish it by converting oxalic acid (OA) to glycolic acid (an alcohol) in the cathode by exploiting the electrocatalytic reduction of −COOH functionalities to alcoholic compounds. It is well-known that alcohols are safer energy carrier molecules and that consequently their production in batteries during electricity generation will be a distinct progress in the sustainable energy landscape. , The proposed Zn-fuel synthesizer battery consists of a Zn anode housed in 6 M KOH as the anodic half-cell and a Pb electrode dipped in 2 M H 2 SO 4 containing 0.7 M OA as the cathodic half-cell. The Pb electrode was chosen as the cathodic electrocatalyst because of its electrocatalytic ability to reduce OA to alcoholic compounds. , The single electrode potentials of the Zn electrode in alkaline medium (6 M KOH) and Pb electrode in acidified OA solution (0.7 M OA in 2 M H 2 SO 4 ) (Figure a) indicate that OA can be an electron acceptor on a Pb cathode in the proposed Zn-organic reactor battery.…”