A Nitrogen-Doped Carbon Catalyst for Electrochemical CO 2 Conversion to CO with High Selectivity and Current Density

• Published in: ChemSusChem 2017-03, Vol.10 (6), p.1094-1099
• Main Authors: Jhong, Huei-Ru Molly, Tornow, Claire E, Smid, Bretislav, Gewirth, Andrew A, Lyth, Stephen M, Kenis, Paul J A
• Format: Article
• Language: English
• Subjects: Carbon - chemistry; Carbon Dioxide - chemistry; Carbon Monoxide - chemistry; Catalysis; Electric Conductivity; Electrochemistry; Electrodes; Models, Molecular; Molecular Conformation; Nanocomposites - chemistry; Nanotubes, Carbon - chemistry; Nitriles - chemistry; Nitrogen - chemistry; Oxidation-Reduction
• ISSN: 1864-5631; 1864-564X
• DOI: 10.1002/cssc.201600843

We report characterization of a non-precious metal-free catalyst for the electrochemical reduction of CO to CO; namely, a pyrolyzed carbon nitride and multiwall carbon nanotube composite. This catalyst exhibits a high selectivity for production of CO over H (approximately 98 % CO and 2 % H ), as well as high activity in an electrochemical flow cell. The CO partial current density at intermediate cathode potentials (V=-1.46 V vs. Ag/AgCl) is up to 3.5× higher than state-of-the-art Ag nanoparticle-based catalysts, and the maximum current density is 90 mA cm . The mass activity and energy efficiency (up to 48 %) were also higher than the Ag nanoparticle reference. Moving away from precious metal catalysts without sacrificing activity or selectivity may significantly enhance the prospects of electrochemical CO reduction as an approach to reduce atmospheric CO emissions or as a method for load-leveling in relation to the use of intermittent renewable energy sources.