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Title: CO-CO coupling on Cu facets: Coverage, strain and field effects

Abstract

We present a DFT study on the effect of coverage, strain, and electric field on CO-CO coupling energetics on Cu (100), (111), and (211). Our calculations indicate that CO-CO coupling is facile on all three facets in the presence of a cation-induced electric field in the Helmholtz plane, with the lowest barrier on Cu(100). The CO dimerization pathway is therefore expected to play a role in C 2 formation at potentials negative of the Cu potential of zero charge, corresponding to CO 2/CO reduction conditions at high pH. Both increased *CO coverage and tensile strain further improve C-C coupling energetics on Cu (111) and (211). Since CO dimerization is facile on all 3 Cu facets, subsequent surface hydrogenation steps may also play an important role in determining the overall activity towards C 2 products. Adsorption of *CO, *H, and *OH on the 3 facets were investigated with a Pourbaix analysis. Here, the (211) facet has the largest propensity to co-adsorb *CO and *H, which would favor surface hydrogenation following CO dimerization.

Authors:
 [1];  [1];  [2];  [2]
  1. Stanford Univ., Stanford, CA (United States)
  2. Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)
Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1349297
Grant/Contract Number:
AC02-76SF00515; SC0004993
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Surface Science
Additional Journal Information:
Journal Volume: 654; Journal Issue: C; Journal ID: ISSN 0039-6028
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; electrocatalysis; CO2 reduction; C-C coupling; CO dimerization

Citation Formats

Sandberg, Robert B., Montoya, Joseph H., Chan, Karen, and Nørskov, Jens K. CO-CO coupling on Cu facets: Coverage, strain and field effects. United States: N. p., 2016. Web. doi:10.1016/j.susc.2016.08.006.
Sandberg, Robert B., Montoya, Joseph H., Chan, Karen, & Nørskov, Jens K. CO-CO coupling on Cu facets: Coverage, strain and field effects. United States. doi:10.1016/j.susc.2016.08.006.
Sandberg, Robert B., Montoya, Joseph H., Chan, Karen, and Nørskov, Jens K. 2016. "CO-CO coupling on Cu facets: Coverage, strain and field effects". United States. doi:10.1016/j.susc.2016.08.006. https://www.osti.gov/servlets/purl/1349297.
@article{osti_1349297,
title = {CO-CO coupling on Cu facets: Coverage, strain and field effects},
author = {Sandberg, Robert B. and Montoya, Joseph H. and Chan, Karen and Nørskov, Jens K.},
abstractNote = {We present a DFT study on the effect of coverage, strain, and electric field on CO-CO coupling energetics on Cu (100), (111), and (211). Our calculations indicate that CO-CO coupling is facile on all three facets in the presence of a cation-induced electric field in the Helmholtz plane, with the lowest barrier on Cu(100). The CO dimerization pathway is therefore expected to play a role in C2 formation at potentials negative of the Cu potential of zero charge, corresponding to CO2/CO reduction conditions at high pH. Both increased *CO coverage and tensile strain further improve C-C coupling energetics on Cu (111) and (211). Since CO dimerization is facile on all 3 Cu facets, subsequent surface hydrogenation steps may also play an important role in determining the overall activity towards C2 products. Adsorption of *CO, *H, and *OH on the 3 facets were investigated with a Pourbaix analysis. Here, the (211) facet has the largest propensity to co-adsorb *CO and *H, which would favor surface hydrogenation following CO dimerization.},
doi = {10.1016/j.susc.2016.08.006},
journal = {Surface Science},
number = C,
volume = 654,
place = {United States},
year = 2016,
month = 8
}

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