CO₂ electroreduction on copper-cobalt nanoparticles: Size and composition effect

TY - JOUR

T1 - CO2 electroreduction on copper-cobalt nanoparticles

T2 - Size and composition effect

AU - Bernal, M.

AU - Bagger, A.

AU - Scholten, F.

AU - Sinev, I.

AU - Bergmann, A.

AU - Ahmadi, M.

AU - Rossmeisl, J.

AU - Cuenya, B. Roldan

PY - 2018

Y1 - 2018

N2 - Understanding the changes that a catalyst may experience on its surface during a reaction is crucial in order to establish structure/composition-reactivity correlations. Here, we report on bimetallic size-selected Cu100-xCox nanoparticle (NP) catalysts for CO2 electroreduction reaction (CO2RR) and we identify the optimum Cu/Co ratio and NP size leading to improved activity and selectivity. Operando X-ray absorption spectroscopy (XAS) and quasi in situ X-ray photoelectron spectroscopy (XPS) provided insight into the morphological, structural, and chemical transformations underwent by the CuCo NPs during CO2RR. We illustrate that the as-prepared state of the bimetallic NPs is drastically different from the structure and surface composition of the working catalyst. Under electrochemical conditions, a reduction of both initially oxidized metallic species was observed, accompanied by Cu surface segregation. Density functional theory (DFT) results from a Cu3X model were used to describe the surface segregation. In order to extract mechanistic understanding, the activity of the experimental Cu and CuCo NPs towards CO2RR was described via DFT in terms of the interaction of Cu facets under expansion and compression with key reaction intermediates, in particular CO* and COOH*.

AB - Understanding the changes that a catalyst may experience on its surface during a reaction is crucial in order to establish structure/composition-reactivity correlations. Here, we report on bimetallic size-selected Cu100-xCox nanoparticle (NP) catalysts for CO2 electroreduction reaction (CO2RR) and we identify the optimum Cu/Co ratio and NP size leading to improved activity and selectivity. Operando X-ray absorption spectroscopy (XAS) and quasi in situ X-ray photoelectron spectroscopy (XPS) provided insight into the morphological, structural, and chemical transformations underwent by the CuCo NPs during CO2RR. We illustrate that the as-prepared state of the bimetallic NPs is drastically different from the structure and surface composition of the working catalyst. Under electrochemical conditions, a reduction of both initially oxidized metallic species was observed, accompanied by Cu surface segregation. Density functional theory (DFT) results from a Cu3X model were used to describe the surface segregation. In order to extract mechanistic understanding, the activity of the experimental Cu and CuCo NPs towards CO2RR was described via DFT in terms of the interaction of Cu facets under expansion and compression with key reaction intermediates, in particular CO* and COOH*.

KW - CO2 electroreduction

KW - Copper

KW - Electrochemistry

KW - Nanoparticle

KW - Operando spectroscopy

KW - Surface segregation

U2 - 10.1016/j.nanoen.2018.08.027

DO - 10.1016/j.nanoen.2018.08.027

M3 - Journal article

AN - SCOPUS:85052003245

SN - 2211-2855

VL - 53

SP - 27

EP - 36

JO - Nano Energy

JF - Nano Energy

ER -