Tandem single atom electrocatalyst realizes reduction of CO2 to ethanol. Credit: DICP
A recent breakthrough in CO2 reduction research involves a newly developed Sn-based catalyst that efficiently produces ethanol, representing a significant step forward in renewable energy technology.
The electrochemical CO2 reduction reaction (CO2RR) into carbon-based fuels provides a promising strategy to mitigate CO2 emission and promotes the utilization of renewable energy.
Challenges in CO2 Reduction
Cn (n≥2) liquid products are desirable because of their high energy densities and ease of storage. However, manipulation of C-C coupling pathway remains a challenge due to the limited mechanistic understanding.
Breakthrough Research
Recently, a research group led by Profs. Tao Zhang and Yanqiang Huang from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) has developed a Sn-based tandem electrocatalyst (SnS2@Sn1-O3G), which could reproducibly yield ethanol with a Faradaic efficiency of up to 82.5% at -0.9 VRHE and a geometric current density of 17.8 mA/cm2.
The study was published recently in the scientific journal Nature Energy.
Catalyst Development
The researchers fabricated the SnS2@Sn1-O3G through a solvothermal reaction of SnBr2 and thiourea on a three-dimensional carbon foam. The electrocatalyst comprised SnS2 nanosheets and atomically dispersed Sn atoms (Sn1-O3G).
Mechanistic Insights
A mechanistic study showed that this Sn1-O3G could respectively adsorb *CHO and *CO(OH) intermediates, therefore promoting C-C bond formation through an unprecedented formyl-bicarbonate coupling pathway.
Moreover, by using isotopically labeled reactants, the researchers traced the pathway of C atoms in the final C2 product formed over the catalyst of Sn1-O3G. This analysis suggested that the methyl C in the product comes from formic acidAny substance that when dissolved in water, gives a pH less than 7.0, or donates a hydrogen ion.” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]”>acid whereas the methylene C was from CO2.
Conclusion
“Our study provides an alternative platform for C–C bond formation for ethanol synthesis and offers a strategy for manipulating CO2 reduction pathways towards desired products,” said Prof. Huang.
Reference: “A tin-based tandem electrocatalyst for CO2 reduction to ethanol with 80% selectivity” by Jie Ding, Hong Bin Yang, Xue-Lu Ma, Song Liu, Wei Liu, Qing Mao, Yanqiang Huang, Jun Li, Tao Zhang and Bin Liu, 30 October 2023, Nature Energy.
DOI: 10.1038/s41560-023-01389-3
Source: SciTechDaily
