Título:	Selective electrochemical CO2 reduction to formate at industrial current densities using 2D Bi2O2CO3 nanosheets.
Autoria:	TOMAS, M. J. SEVENE, D. R. MARRENJO, G. J. SILVA, C. P. M. OLIVEIRA, J. A. de RIBEIRO, C. LOPES, O. F.
Afiliação:	FEDERAL UNIVERSITY OF UBERLANDIA; FEDERAL UNIVERSITY OF UBERLANDIA; FEDERAL UNIVERSITY OF UBERLANDIA; FEDERAL UNIVERSITY OF UBERLANDIA; FEDERAL UNIVERSITY OF SAO CARLOS; CAUE RIBEIRO DE OLIVEIRA, CNPDIA; FEDERAL UNIVERSITY OF UBERLANDIA.
Ano de publicação:	2026
Referência:	Electrochimica Acta, v. 559, 148623, 2026.
Conteúdo:	Electrochemical CO2 reduction to formate (HCOO-) represents an efficient strategy to mitigate CO2 emissions while producing value-added chemicals. However, the reaction typically requires high overpotential and suffers from low selectivity and current density. This work reports the development of Bi2O2CO3 (BOC) nanosheets synthesized hydrothermally with urea at 90 ◦C (BOC-90) and 150 ◦C (BOC-150), evaluated in a flow-cell configuration with gas diffusion electrodes. A Bi2O2CO3 sample calcined at 400 ◦C (Bi2O3–400) was also investigated for comparison. Both BOC-90 and BOC-150 outperformed Bi2O3–400 and a commercial BOC sample in HCOO- production. Notably, BOC-150 achieved a current density of -140 mA cm-2 and a Faradaic efficiency (FE) of 95% for HCOO- at -1.2 V vs. RHE in 0.5 M KOH. Optimizing the electrolyte concentration (1.0 M KOH) and electrode composition (75% BOC-150, 25% carbon black) further enhanced performance, yielding -250 mA cm-2 with FE for HCOO- (FEHCOO-) above 90%. EIS showed that BOC-150 has the lowest charge-transfer resis tance, while ECSA measurements confirmed its highest active surface area, jointly explaining its enhanced ECR performance. NIR and XPS analyses revealed that strongly adsorbed water and Bi dissolution reduced BOC-90 stability, while BOC-150 maintained structural integrity and favorable surface composition. The electrode exhibited stable operation for 6 h, maintaining a Faradaic efficiency above 80% throughout the electrolysis. These findings demonstrate that BOC nanosheets, particularly those obtained under optimized hydrothermal conditions, are highly efficient and durable electrocatalysts for CO2 reduction to HCOO- under industrially relevant conditions.
Palavras-chave:	CO2 electroreduction Hydrothermal synthesis Bismuth-based catalysts
ISSN:	0013-4686
Digital Object Identifier:	https://doi.org/10.1016/j.electacta.2026.148623
Tipo do material:	Artigo de periódico
Acesso:	openAccess
Aparece nas coleções:	Artigo em periódico indexado (CNPDIA)