High-Performance Electrochemical CO 2 Reduction Cells Based on Non-noble Metal Catalysts

The promise and challenge of electrochemical mitigation of CO 2 calls for innovations on both catalyst and reactor levels. In this work, enabled by our high-performance and earth-abundant CO 2 electroreduction catalyst materials, we developed alkaline microflow electrolytic cells for energy-efficient, selective, fast, and durable CO 2 conversion to CO and HCOO – . With a cobalt phthalocyanine-based cathode catalyst, the CO-selective cell starts to operate at a 0.26 V overpotential and reaches a Faradaic efficiency of 94% and a partial current density of 31 mA/cm 2 at a 0.56 V overpotential. With a SnO 2 -based cathode catalyst, the HCOO – -selective cell starts to operate at a 0.76 V overpotential and reaches a Faradaic efficiency of 82% and a partial current density of 113 mA/cm 2 at a 1.36 V overpotential. In contrast to previous studies, we found that the overpotential reduction from using the alkaline electrolyte is mostly contributed by a pH gradient near the cathode surface.