Work

Continuous-flow electrosynthesis of urea and oxalic acid by CO2-nitrate reduction and glycerol oxidation

Year: 2024

Type: article

Abstract: ABSTRACT Urea and oxalic acid are critical component in various chemical manufacturing industries. However, achieving simultaneous generation of urea and oxalic acid in a continuous-flow electrolyzer is a challenge. Herein, we report a continuous-flow electrolyzer equipped with 9-square centimeter-effective area gas diffusion electrodes (GDE) which can simultaneously catalyze the glycerol oxidation reaction in the anode region and the reduction reaction of CO 2 and nitrate in the cathode region, producing oxalic acid and urea at both the anode and cathode , respectively. The current density at low cell voltage (0.9 V) remained above 18.7 mA cm –2 for 10 consecutive electrolysis cycles (120 h in total), and the Faraday efficiency of oxalic acid (67.1%) and urea (70.9%) did not decay. Experimental and theoretical studies show that in terms of the formation of C–N bond at the cathode, Pd-sites can provide protons for the hydrogenation process of CO 2 and NO 3 – , Cu-sites can promote the generation of *COOH and Bi-sites can stabilize *COOH. In addition, in terms of glycerol oxidation , the introduction of Cu and Bi into Pd metallene promotes the oxidation of hydroxyl groups and the cleavage of C–C bond in glycerol molecules, respectively.

Source: CHINESE JOURNAL OF CATALYSIS (CHINESE VERSION)

DOI: 10.1016/s1872-2067(24)60085-9

Authors: Shuanglong Zhou, Yue Shi, Yu Dai, Tianrong Zhan, Jianping Lai, Lei Wang

Institution: Qingdao University of Science and Technology

Language: English

Topic: CO2 Reduction Techniques and Catalysts

Subfield: Renewable Energy, Sustainability and the Environment

Field: Energy

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: hybrid

Estimated APC paid: $3,000