CO2 Reduction to Hydrocarbons via Copper Gas-Diffusion Electrocatalysts

There have been many attempts to find efficient approaches to reduce CO2 to various organic compounds. Major challenges remain to realize development of an efficient, inexpensive, and durable catalytic system, including identification of appropriate design principles and elucidation of the free energy landscapes of these reactions. Modern carbon emission mitigation efforts to date have mainly focused on carbon capture and sequestration. Despite the remaining challenges in developing CO2 conversion technologies, the need is clear that in order to reduce risk and offset the cost of carbon capture and sequestration, development of CO2 utilization technologies to generate value-added products is required. A promising approach for CO2 conversion is electrocatalytic reduction, which can be achieved on various cathode materials. Of these, only copper is known to generate hydrocarbons as majority products. While various researchers have demonstrated CO2 reduction to hydrocarbons such as ethylene, the technologies developed to date typically suffer from relatively low conversion selectivity and overall current density, and high overpotentials, all of which contribute to high capital and operating costs in installed systems. Improved catalysts and catalyst fabrication methods are urgently needed to address these challenges. Phase I will investigate pulsed electrodeposition of copper onto gas- diffusion electrode substrates as a means for low-cost fabrication of high-efficiency electrocatalysts for the production of hydrocarbons from CO2. Electroanalysis and electrocatalytic testing will be performed on the electrocatalysts in order to evaluate parameters such as their selectivity for hydrocarbons such as ethylene and the total current density they are able to support. The catalysts will be tested in a benchtop- scale flow electroreactor in order to provide preliminary data on their performance in a context comparable to that of a large-scale industrial installation. Preliminary techno-economic and scale-up analyses will be performed in order to provide high-level metrics for the potential industrial-scale viability of the proposed process. Commercial Applications and Other Benefits: Hydrocarbons such as ethylene are of critical importance to the chemical industry in the Nation and worldwide as platform feedstocks, and the development of methods to enable conversion of CO2 to these chemicals represents a valuable goal within the CO2 utilization sphere. The proposed CO2 utilization technique also has the potential to positively impact society by improving the earth’s carbon balance, reducing greenhouse gas admissions, and enhancing the robustness of the supply chain for the liquid fuel infrastructure of the Nation.