Graphene-Supported Monometallic and Bimetallic Dimers
for Electrochemical CO<sub>2</sub> Reduction
Haiying He
Christopher Morrissey
Larry A. Curtiss
Peter Zapol
10.1021/acs.jpcc.8b07887.s001
https://acs.figshare.com/articles/journal_contribution/Graphene-Supported_Monometallic_and_Bimetallic_Dimers_for_Electrochemical_CO_sub_2_sub_Reduction/7448213
Bimetallic
catalysts are attractive alternatives to extend the
parameter space that can be tuned for support interactions and catalytic
performance. In this study, we have investigated the smallest bimetallic
catalystsî—¸dimersî—¸supported on defective graphene for
the electrochemical reduction of CO<sub>2</sub> to CH<sub>4</sub> based
on a first-principles approach and the computational hydrogen electrode
model. The monometallic and bimetallic dimers formed from Group 10
(Ni, Pd, Pt) and group 11 (Cu, Ag, Au) elements are characterized
by a positively charged anchoring atom occupying the vacancy site
of graphene and a neutral or slightly negatively charged antenna atom
sticking out from the graphene surface. The strong selective binding
of these dimers ensures their high stability. Possible rate-limiting
steps are identified from the full reaction pathways to generate CH<sub>4</sub>. Overall, Pt<sub>2</sub>, AgNi, Pd<sub>2</sub>, and AgPt
are the best candidates with the lowest overpotential values of 0.37,
0.69, 0.69, and 0.76 V, respectively. It is found that the alloy effect
and the interaction with support help to optimize the property. These
metallic dimers, however, retain nonmonotonous property relationships
that give opportunity to go beyond scaling behavior and look for a
few atom catalysts that have unique properties to reduce rate-limiting
potentials and improve the catalytic performance.
2018-11-26 00:00:00
dimers
Pt
Pd
hydrogen electrode model
bimetallic
nonmonotonous property relationships
CH 4
interaction
graphene
Possible rate-limiting steps
performance
Electrochemical CO 2 Reduction Bimetallic catalysts