Quantifying local pH changes in carbonate electrolyte during copper-catalysed $$\hbox {CO}_2$$ electroreduction using in operando $$^{13}\hbox {C}$$ NMR

Scientific Reports, vol. 12, pp. 8274

Abstract

The electrochemical carbon dioxide reduction on copper attracted considerable attention within the last decade, since Cu is the only elemental transition metal that catalyses the formation of short-chain hydrocarbons and alcohols. Research in this field is mainly focused on understanding the reaction mechanism in terms of adsorbates and intermediates. Furthermore, dynamic changes in the micro-environment of the catalyst, i.e. local pH and [Formula: see text] concentration values, play an equivalently important role in the selectivity of product formation. In this study, we present an in operando [Formula: see text] nuclear magnetic resonance technique that enables the simultaneous measurement of pH and [Formula: see text] concentration in electrode vicinity during electroreduction. The influence of applied potential and buffer capacity of the electrolyte on the formation of formate is demonstrated. Theoretical considerations are confirmed experimentally and the importance of the interplay between catalyst and electrolyte is emphasised.

Authors 4

1. Michael Schatz corresponding Aachen Institute of Technical and Macromolecular Chemistry

   Forschungszentrum Jülich · RWTH Aachen University

   Affiliation as printed

   Institute of Energy and Climate Research, Fundamental Electrochemistry (IEK-9), Forschungszentrum Jülich, 52425 Jülich, Germany

   Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, 52074 Aachen, Germany

   Institute of Energy and Climate Research, Fundamental Electrochemistry (IEK-9), Forschungszentrum Jülich, 52425, Jülich, Germany

2. Sven Jovanovic

   Forschungszentrum Jülich

   Affiliation as printed

   Institute of Energy and Climate Research, Fundamental Electrochemistry (IEK-9), Forschungszentrum Jülich, 52425 Jülich, Germany

   Institute of Energy and Climate Research, Fundamental Electrochemistry (IEK-9), Forschungszentrum Jülich, 52425, Jülich, Germany

3. Rüdiger‐A. Eichel Aachen Institute of Physical Chemistry

   Forschungszentrum Jülich · RWTH Aachen University

   Affiliation as printed

   Institute of Energy and Climate Research, Fundamental Electrochemistry (IEK-9), Forschungszentrum Jülich, 52425 Jülich, Germany

   Institute of Physical Chemistry, RWTH Aachen University, 52074 Aachen, Germany

   Institute of Energy and Climate Research, Fundamental Electrochemistry (IEK-9), Forschungszentrum Jülich, 52425, Jülich, Germany

4. Josef Granwehr Aachen Institute of Technical and Macromolecular Chemistry

   Forschungszentrum Jülich · RWTH Aachen University

   Affiliation as printed

   Institute of Energy and Climate Research, Fundamental Electrochemistry (IEK-9), Forschungszentrum Jülich, 52425 Jülich, Germany

   Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, 52074 Aachen, Germany

   Institute of Energy and Climate Research, Fundamental Electrochemistry (IEK-9), Forschungszentrum Jülich, 52425, Jülich, Germany