Industrial electrooxidation of glutaraldehyde waste to glutaric acid via tailoring OH* coverage

Abstract

Glutaric acid (GA) is an important organic chemical raw material, but current industrialized production routes suffer from process complexity, low yield, and the use of high-polluting oxidants. Electrocatalytic synthesis of GA from glutaraldehyde waste provides a sustainable alternative to highly polluting conventional production methods. However, industrial production still faces challenges such as low energy efficiency (EE) and selectivity. Here, we present a commercially feasible GA electrosynthesis strategy with an EE of 55.4%, which significantly exceeds the 34.8% EE deemed economically viable based on a technical–economic analysis. We demonstrate that the high selectivity of glutaric acid (97%) is achieved through hydroxyl spillover from the introduction of Fe, which reduces the OH* coverage on the NiOOH site to inhibit the over-oxidation of glutaraldehyde. The bifunctional electrocatalyst-catalyzed HER–GOR system exhibits high Faraday efficiencies at both electrodes (99.8% for the HER and 92.7% for the GOR) and excellent stability after 24 hours of continuous operation at 500 mA cm⁻², achieving an EE of 55.4%.