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A Precious‐Metal‐Free Hybrid Electrolyzer for Alcohol Oxidation Coupled to CO 2 ‐to‐Syngas Conversion
Author(s) -
Bajada Mark A.,
Roy Souvik,
Warnan Julien,
Abdiaziz Kaltum,
Wagner Andreas,
Roessler Maxie M.,
Reisner Erwin
Publication year - 2020
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202002680
Subject(s) - electrocatalyst , electrolysis , chemistry , syngas , faraday efficiency , cobalt , mesoporous material , alcohol oxidation , chemical engineering , cathode , inorganic chemistry , anode , electrochemistry , catalysis , organic chemistry , electrolyte , electrode , engineering
Electrolyzers combining CO 2 reduction (CO 2 R) with organic substrate oxidation can produce fuel and chemical feedstocks with a relatively low energy requirement when compared to systems that source electrons from water oxidation. Here, we report an anodic hybrid assembly based on a (2,2,6,6‐tetramethylpiperidin‐1‐yl)oxyl (TEMPO) electrocatalyst modified with a silatrane‐anchor ( STEMPO ), which is covalently immobilized on a mesoporous indium tin oxide ( meso ITO) scaffold for efficient alcohol oxidation (AlcOx). This molecular anode was subsequently combined with a cathode consisting of a polymeric cobalt phthalocyanine on carbon nanotubes to construct a hybrid, precious‐metal‐free coupled AlcOx–CO 2 R electrolyzer. After three‐hour electrolysis, glycerol is selectively oxidized to glyceraldehyde with a turnover number (TON) of ≈1000 and Faradaic efficiency (FE) of 83 %. The cathode generated a stoichiometric amount of syngas with a CO:H 2 ratio of 1.25±0.25 and an overall cobalt‐based TON of 894 with a FE of 82 %. This prototype device inspires the design and implementation of nonconventional strategies for coupling CO 2 R to less energy demanding, and value‐added, oxidative chemistry.