Interfacial Chemistry in the Electrocatalytic Hydrogenation of CO2 over C-Supported Cu-Based Systems

Diego Gianolio; Michael D Higham; Matthew G Quesne; Matteo Aramini; Ruoyu Xu; Alex I Large; Georg Held; Juan-Jesús Velasco-Vélez; Michael Haevecker; Axel Knop-Gericke; Chiara Genovese; Claudio Ampelli; Manfred Erwin Schuster; Siglinda Perathoner; Gabriele Centi; C Richard A Catlow; Rosa Arrigo

doi:10.1021/acscatal.3c01288

Interfacial Chemistry in the Electrocatalytic Hydrogenation of CO₂ over C-Supported Cu-Based Systems

ACS Catal. 2023 Apr 14;13(9):5876-5895. doi: 10.1021/acscatal.3c01288. eCollection 2023 May 5.

Authors

Diego Gianolio¹, Michael D Higham^{2

3

4}, Matthew G Quesne^{2

3}, Matteo Aramini¹, Ruoyu Xu⁵, Alex I Large¹, Georg Held¹, Juan-Jesús Velasco-Vélez^{6

7}, Michael Haevecker^{6

7}, Axel Knop-Gericke^{6

7}, Chiara Genovese⁸, Claudio Ampelli⁸, Manfred Erwin Schuster⁹, Siglinda Perathoner⁸, Gabriele Centi⁸, C Richard A Catlow^{1

2

3

4}, Rosa Arrigo^{1

10}

Affiliations

¹ Diamond Light Source Ltd., Harwell Science & Innovation Campus, Didcot, Oxfordshire OX11 0DE, U.K.
² Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, Wales CF10 3AT, U.K.
³ UK Catalysis Hub, Research Complex at Harwell, Rutherford Appleton Laboratory, R92, Harwell, Oxfordshire OX11 0FA, U.K.
⁴ Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K.
⁵ Department of Chemical Engineering, University College London, 20 Gordon Street, London WC1H 0AJ, U.K.
⁶ Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany.
⁷ Department of Inorganic Chemistry, Fritz-Haber-Institut der Max-Planck Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany.
⁸ Department of ChiBioFarAm, ERIC aisbl and CASPE/INSTM, University of Messina, V. le F.Stagno D' Alcontres 31, 98166 Messina, Italy.
⁹ Johnson Matthey Technology Centre, Reading RG4 9NH, U.K.
¹⁰ School of Science, Engineering and Environment, University of Salford, Cockcroft Building, Salford, Greater Manchester M5 4WT, U.K.

Abstract

Operando soft and hard X-ray spectroscopic techniques were used in combination with plane-wave density functional theory (DFT) simulations to rationalize the enhanced activities of Zn-containing Cu nanostructured electrocatalysts in the electrocatalytic CO₂ hydrogenation reaction. We show that at a potential for CO₂ hydrogenation, Zn is alloyed with Cu in the bulk of the nanoparticles with no metallic Zn segregated; at the interface, low reducible Cu(I)-O species are consumed. Additional spectroscopic features are observed, which are identified as various surface Cu(I) ligated species; these respond to the potential, revealing characteristic interfacial dynamics. Similar behavior was observed for the Fe-Cu system in its active state, confirming the general validity of this mechanism; however, the performance of this system deteriorates after successive applied cathodic potentials, as the hydrogen evolution reaction then becomes the main reaction pathway. In contrast to an active system, Cu(I)-O is now consumed at cathodic potentials and not reversibly reformed when the voltage is allowed to equilibrate at the open-circuit voltage; rather, only the oxidation to Cu(II) is observed. We show that the Cu-Zn system represents the optimal active ensembles with stabilized Cu(I)-O; DFT simulations rationalize this observation by indicating that Cu-Zn-O neighboring atoms are able to activate CO₂, whereas Cu-Cu sites provide the supply of H atoms for the hydrogenation reaction. Our results demonstrate an electronic effect exerted by the heterometal, which depends on its intimate distribution within the Cu phase and confirms the general validity of these mechanistic insights for future electrocatalyst design strategies.