Interfacial chemistry in the electrocatalytic hydrogenation of CO2 over C-supported Cu-based systems

DOI: 10.1021/acscatal.3c01288

Authors: Diego Gianolio (Diamond Light Source) , Michael D. Higham (Cardiff University; UK Catalysis Hub, Research Complex at Harwell; University College London) , Matthew G. Quesne (Cardiff University; UK Catalysis Hub, Research Complex at Harwell) , Matteo Aramini (Diamond Light Source) , Ruoyu Xu (University College London) , Alex I. Large (Diamond Light Source) , Georg Held (Diamond Light Source) , Juan-Jesús Velasco-Vélez (Max-Planck-Institut für Chemische Energiekonversion; Fritz-Haber-Institut der Max-Planck Gesellschaft) , Michael Haevecker (Max-Planck-Institut für Chemische Energiekonversion; Fritz-Haber-Institut der Max-Planck Gesellschaft) , Axel Knop-Gericke (Max-Planck-Institut für Chemische Energiekonversion; Fritz-Haber-Institut der Max-Planck Gesellschaft) , Chiara Genovese (University of Messina) , Claudio Ampelli (University of Messina) , Manfred Erwin Schuster (Johnson Matthey Technology Centre) , Siglinda Perathoner (University of Messina) , Gabriele Centi (University of Messina) , C. Richard A. Catlow (Diamond Light Source; Cardiff University; UK Catalysis Hub, Research Complex at Harwell; University College London) , Rosa Arrigo (Diamond Light Source; University of Salford)
Co-authored by industrial partner: Yes

Type: Journal Paper
Journal: Acs Catalysis

State: Published (Approved)
Published: April 2023
Diamond Proposal Number(s): 24919

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.

Journal Keywords: operando spectroscopy; CO2RR; Cu, Zn, Fe electrocatalysts; DFT; XAFS

Subject Areas: Chemistry


Instruments: B18-Core EXAFS

Added On: 17/04/2023 08:40

Documents:
acscatal.3c01288.pdf

Discipline Tags:

Physical Chemistry Catalysis Chemistry

Technical Tags:

Spectroscopy X-ray Absorption Spectroscopy (XAS) Extended X-ray Absorption Fine Structure (EXAFS) X-ray Absorption Near Edge Structure (XANES)