Binary copper-bismuth catalysts for the electrochemical reduction of CO2: study on surface properties and catalytic activity
2022
Azenha, Cátia | Mateos Pedrero, Cecilia | Álvarez Guerra, Manuel | Irabien Gulías, Ángel | Mendes, Adélio | Universidad de Cantabria
A series of CuBi catalysts were prepared with different Bi loadings and tested for the electrochemical reduction of CO2 (ERCO2). The developed catalysts were tested on a filter-press cell, and the influence of the catholyte on the catalytic performance was assessed. Catalyst #20C was found to be very selective for formate production, with a faradaic efficiency (FE) of 86.4 %, when Cl– ions are present in the catholyte solution. The presence of weak CO2 adsorption sites on the catalyst surface favors the formation of non-coordinated and monodentate carbonates after CO2 adsorption, resulting in enhanced formate formation through an outer-sphere mechanism. For catalyst #50C, an unprecedented propane selectivity was recorded (FE of 85.4 %), being the first high-efficiency catalyst for the ERCO2 to propane ever reported. This remarkable catalytic behavior was attributed to strong CO2 adsorption sites on the catalyst surface and higher CO2 and CO adsorption capacity. It is also proposed that a bidentate carbonate is a key intermediate for the ERCO2 to propane, which is preferably formed when strong Lewis acid and base sites are present on the catalyst surface.
显示更多 [+] 显示较少 [-]C. Azenha is grateful to the Portuguese Foundation for Science and Technology (FCT) for the doctoral grant (reference SFRH/BD/128768/2017). This work was financially supported by: LA/P/0045/2020 (ALiCE), UIDB/00511/2020 and UIDP/00511/2020 (LEPABE), funded by national funds through FCT/MCTES (PIDDAC); and was performed under the project “SunStorage - Harvesting and storage of solar energy”, POCI-01-0145-FEDER-016387, funded by FEDER funds through COMPETE2020 – Programa Operacional Competitividade e Internacionalização (POCI) and by national funds (PIDDAC) through FCT/MCTES
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