A Metal–Organic Framework derived Cu<sub><i>x</i></sub>O<sub>y</sub>C<sub>z</sub> Catalyst for Electrochemical CO<sub>2</sub> Reduction and Impact of Local pH Change
Nivedita Sikdar, João R. C. Junqueira, Stefan Dieckhöfer, Thomas Quast, Michael Braun, Yanfang Song, Harshitha Barike Aiyappa, Sabine Seisel, Jonas Weidner, Denis Öhl, Corina Andronescu, Wolfgang Schuhmann
Abstract
Abstract Developing highly efficient and selective electrocatalysts for the CO 2 reduction reaction to produce value‐added chemicals has been intensively pursued. We report a series of Cu x O y C z nanostructured electrocatalysts derived from a Cu‐based MOF as porous self‐sacrificial template. Blending catalysts with polytetrafluoroethylene (PTFE) on gas diffusion electrodes (GDEs) suppressed the competitive hydrogen evolution reaction. 25 to 50 wt % teflonized GDEs exhibited a Faradaic efficiency of ≈54 % for C 2+ products at −80 mA cm −2 . The local OH − ions activity of PTFE‐modified GDEs was assessed by means of closely positioning a Pt‐nanoelectrode. A substantial increase in the OH − /H 2 O activity ratio due to the locally generated OH − ions at increasing current densities was determined irrespective of the PTFE amount.