(509ak) CO2RR-to-C2 Enhanced By Confined Organic-Inorganic Interface

Electrochemical CO₂ reduction reaction (CO₂RR) represents a carbon-neutral pathway for valuable C₂ production (i.e., ethylene and ethanol) due to electricity being a renewable resource. For example, by 2035, electric wind power may reach 2800 TWh, enabling CO₂RR to produce 168 billion USD worth of ethylene while consuming 400 MTons/yr of CO₂ emission. Copper is considered as one of the most promising catalysts for CO₂RR-to-C₂, however, there are still challenging issues related to electrical to chemical power efficiency.^[1] This is because: (1) The weak binding energy between CO₂ and Cu leads to a low overall activity; (2) A high energy requirement of CO dimerization causes a limited C₂ selectivity.

Inspired by the confinement effects, confined space between the organic-inorganic interface, i.e., self-assembled monolayers (SAMs) over Cu, is a promising approach to enhance the power efficiency of CO₂RR-to-C₂ by providing stable defect sites, controllable adsorption sites for the key intermediates, and tunable surface electronic properties. Herein, we designed an aminothiolate SAM-modulated Cu catalyst for CO₂RR-to-C₂ using density functional theory (DFT). Our calculations showed that such catalyst can: (1) stabilize less favorable but active Cu facets (i.e., Cu(100) and Cu(211), Figure 1a); (2) enhance the initial activation energy of CO₂ by forming strong C-N bonds and H-bonds between the OCOH and the tail -NH₂ group of the aminothiolates (Figure 1b); (3) lower the energy requirement of CO dimerization by creating confinement effects at the organic-inorganic interface and providing dual organic-inorganic surface-active site (Figure 1c).^[2] These results will lead to a new understanding of electrocatalytic activity and selectivity at the confined interface of organic-inorganic heterogeneous catalysts with the concept being potentially applicable to a wide range of catalytic processes.

References

[1]. Li, J.*; Ozden, A.*; Wan, M.* et al., Nat Commun 2021 (in press).

[2]. Wan, M.; Gu, Z., Che, F., In preparation 2021.