SAC-Cu-CO2RR · Highly Ethanol-Selective Electrocatalytic CO2 Reduction Enabled by Site-Specific Heteroatoms Doped Single Atom Catalysts Supported Cu Clusters

Highly Ethanol-Selective Electrocatalytic CO2 Reduction Enabled by Site-Specific Heteroatoms Doped Single Atom Catalysts Supported Cu Clusters

The COP 28 UN Climate Change Conference in Dubai (2023) conducted the first “global stocktake” of the world’s efforts to address climate change under the Paris Agreement, consenting to hasten the transition from fossil fuels to renewable sources, such as wind and solar power. However, for air transportation, steel, and cement plants et al., adoption of new energy sources necessitates significant technological innovation and cannot be achieved in a short timeframe. To abate these most persistent emissions, electrochemical carbon dioxide reduction reaction (eCO2RR) coupled with renewable electricity, is an elegant technology by utilizing CO2 to produce an alternative energy medium for the current fossil fuel. In this way, we can achieve a net-zero pathway for hard-to-decarbonize sectors. Among all products in eCO2RR, multicarbon (C2+) products have received extensive attention because it can be directly used as fuel in internal combustion engines and industrial power generation. Copper (Cu) has been considered as the predominant electrocatalyst for C2 products via promoting C-C coupling, but with a poor selectivity towards C2+. Therefore, the objective of this project is to design carbon-based single atom catalysts (SACs) supported Cu clusters architecture to let it serve as a high-efficient catalyst for achieving a high C2+ selectivity (> 75%) at a low overpotential. In this project, I prepared Ni-based SACs with high-density of Ni by a modified method. And then, I combined the Ni-based SACs with Cu nanoparticles. Benefiting from the synergistic effect of Ni SACs and Cu nanoparticles, the prepared Ni-SACs/Cu tested in an H-cell and flow cell achieved a faradaic efficiency of ~60% towards C2+ products. During the process of completing this project, I have been thinking about a question: Although eCO2RR is advancing quickly, the laboratory-bench efforts have been achieved by utilizing ultrapure CO2 (99.999%) as feedstock gas. It overlooked the upstream CO2 capture from point source and enrichment processes that expends a major energy and cost, thus reducing the economic benefits for design a real-world eCO2RR system. The electrochemical conversion of CO2-captured solvents (HCO3−), into value-added chemicals can bypass energy-intensive CO2 regeneration. Accordingly, I slightly adjusted the focus of my MSCA project. Following the completion of eCO2RR using Ni-SACs catalysts, I further employed these catalysts—with strategic modifications—for bicarbonate electrocatalysis, achieving excellent performance under high current densities. This approach enables the in-situ generated CO2 to be efficiently reduced into value-added products, thus achieving an integrated CO2 capture and conversion strategy This work provides a straightforward method for the synthesis of hybrid catalysts, which exhibited a good catalytic performance towards eCO2RR and bicarbonate electrocatalysis. It will push catalyst engineering to the next level of development and eCO2RR technology closer to techno-economic profitability. No website has been developed for the project.

Data: CORDIS, © European Union