One of the main contributors to climate change is the emission of greenhouse gases from the extraction, conversion, and use of fossil fuels. Current methods are driven by high temperatures and pressures, making them highly energy-intensive. A transition to more sustainable methods is necessary to mitigate emissions while accommodating demand for the commodities that we use in our daily lives. To achieve this, we can consider repurposing existing waste streams and investigating potential closed-carbon cycles. Electrocatalytically coupling CO2 or CO with oxygenated organic molecules formed as waste or byproducts of biomass conversion processes provides an expansive, tunable platform for achieving desired chemical or fuel products via directed chain elongation. We explore co-electroreduction of COx with model C2 oxygenate molecules to investigate the range of possible C3+ products and probe reaction mechanisms. We explore reaction selectivity and tunability, aiming to maximize the interaction between reactant feed species at catalyst active sites and leverage the reducibility of functional groups on oxygenated C2 molecules. Tuning the identity of the oxygenated C2 molecule is critical, as the presence or absence of reducible double bonds or functional groups provides a means to regulate product selectivity. For example, co-electroreduction of CO2 and oxalate on copper yields higher concentrations of C2+ molecules when compared to pure CO2 reduction, indicating positive molecular interactions to tune product distributions. In addition, these systems are explored as a function of reactant feed rates, electrode composition (solid vs. porous), and reactor geometry (H-cell vs. gas diffusion electrode) to understand impacts of mass transport and kinetics on overall activity and selectivity. Finally, we use in situ attenuated total reflection infrared spectroscopy to investigate changes in catalyst surface adsorbates and probe reaction mechanisms. By analyzing the fundamentals of co-electroreduction, we can move toward an alternative production method to ultimately reduce greenhouse gas emissions.

Co-electroreduction of COx with oxygenated two-carbon species for tunable hydrocarbon production

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.