报告人：王昱沆 博士 多伦多大学
报告题目：Carbon dioxide valorization in gas-diffusion-electrode-based devices
The CO2 utilization offers routes to address climate change concerns and displace the conventional manufacturing processes intensively relying on fossil fuels with a cost-effective and environmentally friendly approach. When powered by renewable electricity, the electroreduction of CO2 is of particular interest in terms of both the storage of intermittent renewables and the production of high-energy-density and economically valuable fuels/chemicals with net-zero emission. Cu-catalyzed CO2 electroreduction features the uniqueness of producing hydrocarbon and C2+ oxygenates, and has been intriguing scientists for decades.
For CO2 electoreduction, the basic idea of using gas-diffusion-electrode-based (GDE-based) systems is to create triple-phase boundaries comprised of CO2, Cu catalysts, and electrolytes. This approach overcomes the limitation of CO2 solubility in aqueous solutions, enhancing the current densities by at least one order of magnitude.
Albeit with the enhanced catalytic current density, compared to non-GDE-based counterparts, the GDE-based electrolyzers do not seem to significantly increase the C2+-product selectivity without rationally designed Cu catalysts. Meanwhile, in GDE-based electrolyzers, inevitable carbonate formation limits the utilization of CO2, blocks the mass transport and de-activates Cu catalysts, and causes additional energy penalty. These hinder the practical implementation of CO2 electroreduction.
Here, we present our most recent advances in designing catalysts and electrolyzers with extraordinary C2+-product selectivity, operating stability, single-pass utilization, and energy efficiency. We provide our newest understanding of catalytic chemistry, catalyst materials science, and device/system engineering for CO2 electro-upgrading.