Nano-electrocatalysis

The atmospheric carbon dioxide concentration has continuously increased due to the intense usage of fossil fuels since the Industrial Revolution, which causes today's consensus on global warming and severe climate change. Among the endeavors for efficiently capturing or utilizing CO2, a direct electrochemical carbon dioxide reduction reaction (eCO2RR) has been spotlighted as an efficient energy storage system. It not only contributes to decreasing carbon dioxide levels in the atmosphere but can also be integrated into energy grids by storing electricity from renewable energy sources as a form of chemical energy, which gives valuable products for the chemical industry.

In our group, a primary research goal is thoroughly understanding eCO2RR using nanostructured catalysts. The field of eCO2RR grows rapidly nowadays, and several works have already been done in the aspect of "structure-property relationships." We have also studied nanoscale chemistry to design better catalysts for eCO2RR.1 For instance, we are looking through the effects of nanostructure synthesis on eventual reduction performances, such as polyol process, overgrowth, galvanic exchange, and pyrolysis of metal-organic frameworks. It was evident that the distinct synthetic protocols precisely determined the catalysts' compositions, oxidation states, and morphology,2,3 resulting in the products' Faradaic efficiency and current density.4

However, the electrochemical system is basically mobile - under the applied potentials, everything changes during the reaction. That is why the original catalyst design is no longer correlated well with the actual reaction properties. Hence, we have to clarify the mechanisms in eCO2RR with both ex-situ and in-situ spectroscopic techniques. Characterizing the exact chemical states during eCO2RR should be conducted by combining multiple results from various spectroscopic and microscopic techniques such as electron microscopy imaging, X-ray diffraction spectroscopy, X-ray photoelectron spectroscopy, and X-Ray absorption spectroscopy. The reactor design is another critical point because the reaction property extremely relies on the structure and conditions of the reaction chambers. The actual electric fields applied for the reactants, diffusion rates, and local pH are highly dependent on the electrochemical device structure. 

Can we apply our catalysts for the practical scale of eCO2RR? We hope to eventually figure out the primary key of catalyst design to developing commercially viable processes and contributing something valuable to human society towards green utopia again. For this aim, we need your assistance to explore new chemistry together. Would you please help us to achieve a dream that makes the Earth green again (MEGA)?

Publications

[1] "Strategies for Designing Nanoparticles for Electro- and Photocatalytic CO2 Reduction", J. Y. Choi, W. Choi, J. W. Park, C. K. Lim, H. Song, Chem. Asian J. 15, 253-265 (2020).

[2] "Branched copper oxide nanoparticles induce highly selective ethylene production by electrochemical carbon dioxide reduction", J. Kim, W. Choi, J. W. Park, C. Kim, M. Kim, H. Song, J. Am. Chem. Soc. 141, 6986-6994 (2019).

[3] "Surface overgrowth on gold nanoparticles modulating high-energy facets for efficient electrochemical CO2 reduction", W. Choi, J. W. Park, W. Park, Y. Jung, H. Song, Nanoscale 13, 14346-14353 (2021).

[4] "FexNi2-xP Alloy Nanocatalysts with Electron-Deficient Phosphorus Enhancing Hydrogen Evolution Reaction in Acidic Media", D. Shin, H. J. Kim, M. Kim, D. Shin, H. Kim, H. Song, S.-I. Choi, ACS Catal. 10, 11665-11673 (2020).