The development of artificial photosynthesis is one of the greatest scientific challenges of our times, not only to protect the environment but also to ensure global economic security. To mimic the natural photosynthesis process, a complete understanding of the natural photosynthesis process at the molecular level is essential to enable the production of inexpensive, lightweight, and high-energy-density fuels. Artificial photosynthesis may involve photo/electrocatalytic H2 generation by water splitting or the use of H2 in combination with atmospheric/industrially sourced CO2 conversion products to provide a continuous supply of high-energy carrier fuels at small/medium scales. Recently, Cu2O has received considerable attention in various energy-conversion applications, including photo/electrochemical hydrogen production and the photo/electrochemical conversion of carbon dioxide (CO2) to energy-carrier fuels. The Cu(I) state, with its d10 electronic configuration, is required for cuprous oxides to exhibit photo/electrochemical and chemical catalytic activity. For electrochemical CO2 reduction, Cu(I) sites are proposed to stabilize reaction intermediates such as CO, carbonates (CO23−), formates (HCOO−), and methoxy (H3CO−) adsorbates, as expected from their high heats of adsorption. Although the Cu(I) state makes these materials attractive, the stability of Cu(I) species toward redox reactions remains an issue to be solved. In this study, we report the novel design of multi-metal based electrocatalysts which may introduce different (other than Cu) active species due to effect of the hetro-atoms on the Cu surface. As a result the reaction intermediates on the surface may be stabilized generating CO exclusively as a reaction product of electrochemical reduction of aqueous CO2 while suppressing the competitive H2 generation. The higher selectivity towards CO generation may be attributed to perturbing the d-band metal center or the geometric effects caused by the second metal center around Cu.
Citation
Rasul, S., & Takanabe, K. (2014). Highly Efficient Electrocatalysts For Recycling Co2. Qatar Foundation Annual Research Conference Proceedings Volume 2014 Issue 1. doi:10.5339/qfarc.2014.eepp0989
