(17g) Low-Cost, Highly Scalable Graphite-Based Catalyst for Electrochemical Methanation of Carbon Dioxide

In recent years, there has been a tremendous interest in the electrochemical conversion of carbon dioxide into useful products such as methane which can be used as a fuel^1,2. If employed on a large scale, electoreduction of CO₂ to fuels could go a long way to reducing our dependence on non-renewable fossil fuels³. Known catalysts for CO₂ electroreduction with high selectivity include gold, silver and copper¹. Gold and silver are not ideal catalysts for this process because they are precious metals and thus very expensive. Copper, although relatively cheaper to use will still incur large costs when employed on a large scale and if constant replacement is required. Thus one of the challenges of making such as process economically viable is the ability to manufacture electrocatalysts for CO₂ electroreduction which are low-cost, easy to manufacture and highly scalable. These characteristics are especially important as catalysts tend to deactivate over time and would therefore be need to be constantly replaced. Herein, we report the synthesis of a graphite-based catalyst which becomes decorated with copper nanoparticles in-situ during CO₂ electoreduction. This catalyst achieved a high selectivity of 60% to methane, which is competitive with copper nanoparticle and foil based catalysts in literature. Crucially, such a catalyst is extremely simple to manufacture, very inexpensive and highly-scalable. Using such a catalyst, we also foresee that a similar approach can be developed for gold and silver, which can dramatically bring down costs for the utilization of these precious metals for CO₂ electoreduction.

1.        Hori, Y. in Modern Aspects of Electrochemistry SE  - 3 (eds. Vayenas, C., White, R. & Gamboa-Aldeco, M.) 42, 89–189 (Springer New York, 2008).

2.        Kuhl, K. P., Cave, E. R., Abram, D. N. & Jaramillo, T. F. New insights into the electrochemical reduction of carbon dioxide on metallic copper surfaces. Energy Environ. Sci. 5, 7050–7059 (2012).

3.        Kim, D., Resasco, J., Yu, Y., Asiri, A. M. & Yang, P. Synergistic geometric and electronic effects for electrochemical reduction of carbon dioxide using gold–copper bimetallic nanoparticles. Nat Commun 5, (2014).