High-performance electrochemical CO2 reduction cells based on non-noble metal catalysts
journal contributionposted on 23.11.2018, 10:19 by Xu Lu, Yueshen Wu, Xiaolei Yuan, Ling Huang, Zishan Wu, Jin XuanJin Xuan, Yifei Wang, Hailiang Wang
The promise and challenge of electrochemical mitigation of CO2 calls for innovations on both catalyst and reactor levels. In this work, enabled by our high-performance and earth-abundant CO2 electroreduction catalyst materials, we developed alkaline microflow electrolytic cells for energy-efficient, selective, fast, and durable CO2 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/cm2 at a 0.56 V overpotential. With a SnO2-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/cm2 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.
This research is supported by the National Science Foundation (Grant CHE-1651717) and the Croucher Fellowship for Postdoctoral Research. X.Y. and L.H. acknowledge the visiting graduate student scholarships from China scholarships Council.
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