Exploring dopant effects in stannic oxide nanoparticles for CO2 electro-reduction to formate

• Published in: Nature communications Vol. 13; no. 1; p. 2205
• Main Authors: Ko, Young-Jin, Kim, Jun-Yong, Lee, Woong Hee, Kim, Min Gyu, Seong, Tae-Yeon, Park, Jongkil, Jeong, YeonJoo, Min, Byoung Koun, Lee, Wook-Seong, Lee, Dong Ki, Oh, Hyung-Suk
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 22.04.2022; Nature Publishing Group; Nature Portfolio
• Subjects: 140/133; 147/143; 639/301/299; 639/638/161/886; 639/638/77/886; 639/638/77/887; Carbon dioxide; Catalysts; Current density; Dopants; Durability; Electrocatalysts; Electrowinning; First principles; Fluorine; Humanities and Social Sciences; multidisciplinary; Nanoparticles; Oxidation; Science; Science (multidisciplinary); Selectivity; Stannic oxide; Tin; Tin dioxide; Tin oxide; Tin oxides; Valence
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-29783-7

The electrosynthesis of formate from CO 2 can mitigate environmental issues while providing an economically valuable product. Although stannic oxide is a good catalytic material for formate production, a metallic phase is formed under high reduction overpotentials, reducing its activity. Here, using a fluorine-doped tin oxide catalyst, a high Faradaic efficiency for formate (95% at 100 mA cm −2 ) and a maximum partial current density of 330 mA cm −2 (at 400 mA cm −2 ) is achieved for the electroreduction of CO 2 . Furthermore, the formate selectivity (≈90%) is nearly constant over 7 days of operation at a current density of 100 mA cm −2 . In-situ/operando spectroscopies reveal that the fluorine dopant plays a critical role in maintaining the high oxidation state of Sn, leading to enhanced durability at high current densities. First-principle calculation also suggests that the fluorine-doped tin oxide surface could provide a thermodynamically stable environment to form HCOO* intermediate than tin oxide surface. These findings suggest a simple and efficient approach for designing active and durable electrocatalysts for the electrosynthesis of formate from CO 2 . Though stannic oxides can catalyze CO 2 electroreduction to formate, the stability of these catalysts has been limited. Here, the authors demonstrate stable fluorine-doped SnO2 materials toward formate production at current densities of >300 mA/cm 2 .