Effect of Chloride Anions on the Synthesis and Enhanced Catalytic Activity of Silver Nanocoral Electrodes for CO2 Electroreduction

Yu Chi Hsieh, Sanjaya D. Senanayake, Yu Zhang, Wenqian Xu, Dmitry Polyansky

Research output: Contribution to journalArticle

119 Citations (Scopus)

Abstract

Metallic silver (Ag) is known as an efficient electrocatalyst for the conversion of carbon dioxide (CO2) to carbon monoxide (CO) in aqueous or nonaqueous electrolytes. However, polycrystalline silver electrocatalysts require significant overpotentials in order to achieve high selectivity toward CO2 reduction, as compared to the side reaction of hydrogen evolution. Here we report a high-surface-area Ag nanocoral catalyst, fabricated by an oxidation-reduction method in the presence of chloride anions in an aqueous medium, for the electro-reduction of CO2 to CO with a current efficiency of 95% at the low overpotential of 0.37 V and the current density of 2 mA cm-2. A lower limit of TOF of 0.4 s-1 and TON > 8.8 × 104 (over 72 h) was estimated for the Ag nanocoral catalyst at an overpotential of 0.49 V. The Ag nanocoral catalyst demonstrated a 32-fold enhancement in surface-area-normalized activity, at an overpotential of 0.49 V, as compared to Ag foil. We found that, in addition to the effect on nanomorphology, the adsorbed chloride anions play a critical role in the observed enhanced activity and selectivity of the Ag nanocoral electrocatalyst toward CO2 reduction. Synchrotron X-ray photoelectron spectroscopy (XPS) studies along with a series of control experiments suggest that the chloride anions, remaining adsorbed on the catalyst surface under electrocatalytic conditions, can effectively inhibit the side reaction of hydrogen evolution and enhance the catalytic performance for CO2 reduction.

Original languageEnglish
Pages (from-to)5349-5356
Number of pages8
JournalACS Catalysis
Volume5
Issue number9
DOIs
Publication statusPublished - Jul 30 2015

Fingerprint

Silver
Anions
Chlorides
Electrocatalysts
Catalyst activity
Negative ions
Electrodes
Catalysts
Carbon Monoxide
Carbon monoxide
Hydrogen
Catalyst selectivity
Synchrotrons
Carbon Dioxide
Metal foil
Electrolytes
Carbon dioxide
Current density
X ray photoelectron spectroscopy
Experiments

Keywords

  • carbon dioxide reduction
  • chloride modification
  • electrocatalysis
  • high selectivity
  • nanoporous Ag

ASJC Scopus subject areas

  • Catalysis

Cite this

Effect of Chloride Anions on the Synthesis and Enhanced Catalytic Activity of Silver Nanocoral Electrodes for CO2 Electroreduction. / Hsieh, Yu Chi; Senanayake, Sanjaya D.; Zhang, Yu; Xu, Wenqian; Polyansky, Dmitry.

In: ACS Catalysis, Vol. 5, No. 9, 30.07.2015, p. 5349-5356.

Research output: Contribution to journalArticle

Hsieh, Yu Chi ; Senanayake, Sanjaya D. ; Zhang, Yu ; Xu, Wenqian ; Polyansky, Dmitry. / Effect of Chloride Anions on the Synthesis and Enhanced Catalytic Activity of Silver Nanocoral Electrodes for CO2 Electroreduction. In: ACS Catalysis. 2015 ; Vol. 5, No. 9. pp. 5349-5356.
@article{a9498f57ef1b4bd1b51f24377a1ce4f5,
title = "Effect of Chloride Anions on the Synthesis and Enhanced Catalytic Activity of Silver Nanocoral Electrodes for CO2 Electroreduction",
abstract = "Metallic silver (Ag) is known as an efficient electrocatalyst for the conversion of carbon dioxide (CO2) to carbon monoxide (CO) in aqueous or nonaqueous electrolytes. However, polycrystalline silver electrocatalysts require significant overpotentials in order to achieve high selectivity toward CO2 reduction, as compared to the side reaction of hydrogen evolution. Here we report a high-surface-area Ag nanocoral catalyst, fabricated by an oxidation-reduction method in the presence of chloride anions in an aqueous medium, for the electro-reduction of CO2 to CO with a current efficiency of 95{\%} at the low overpotential of 0.37 V and the current density of 2 mA cm-2. A lower limit of TOF of 0.4 s-1 and TON > 8.8 × 104 (over 72 h) was estimated for the Ag nanocoral catalyst at an overpotential of 0.49 V. The Ag nanocoral catalyst demonstrated a 32-fold enhancement in surface-area-normalized activity, at an overpotential of 0.49 V, as compared to Ag foil. We found that, in addition to the effect on nanomorphology, the adsorbed chloride anions play a critical role in the observed enhanced activity and selectivity of the Ag nanocoral electrocatalyst toward CO2 reduction. Synchrotron X-ray photoelectron spectroscopy (XPS) studies along with a series of control experiments suggest that the chloride anions, remaining adsorbed on the catalyst surface under electrocatalytic conditions, can effectively inhibit the side reaction of hydrogen evolution and enhance the catalytic performance for CO2 reduction.",
keywords = "carbon dioxide reduction, chloride modification, electrocatalysis, high selectivity, nanoporous Ag",
author = "Hsieh, {Yu Chi} and Senanayake, {Sanjaya D.} and Yu Zhang and Wenqian Xu and Dmitry Polyansky",
year = "2015",
month = "7",
day = "30",
doi = "10.1021/acscatal.5b01235",
language = "English",
volume = "5",
pages = "5349--5356",
journal = "ACS Catalysis",
issn = "2155-5435",
publisher = "American Chemical Society",
number = "9",

}

TY - JOUR

T1 - Effect of Chloride Anions on the Synthesis and Enhanced Catalytic Activity of Silver Nanocoral Electrodes for CO2 Electroreduction

AU - Hsieh, Yu Chi

AU - Senanayake, Sanjaya D.

AU - Zhang, Yu

AU - Xu, Wenqian

AU - Polyansky, Dmitry

PY - 2015/7/30

Y1 - 2015/7/30

N2 - Metallic silver (Ag) is known as an efficient electrocatalyst for the conversion of carbon dioxide (CO2) to carbon monoxide (CO) in aqueous or nonaqueous electrolytes. However, polycrystalline silver electrocatalysts require significant overpotentials in order to achieve high selectivity toward CO2 reduction, as compared to the side reaction of hydrogen evolution. Here we report a high-surface-area Ag nanocoral catalyst, fabricated by an oxidation-reduction method in the presence of chloride anions in an aqueous medium, for the electro-reduction of CO2 to CO with a current efficiency of 95% at the low overpotential of 0.37 V and the current density of 2 mA cm-2. A lower limit of TOF of 0.4 s-1 and TON > 8.8 × 104 (over 72 h) was estimated for the Ag nanocoral catalyst at an overpotential of 0.49 V. The Ag nanocoral catalyst demonstrated a 32-fold enhancement in surface-area-normalized activity, at an overpotential of 0.49 V, as compared to Ag foil. We found that, in addition to the effect on nanomorphology, the adsorbed chloride anions play a critical role in the observed enhanced activity and selectivity of the Ag nanocoral electrocatalyst toward CO2 reduction. Synchrotron X-ray photoelectron spectroscopy (XPS) studies along with a series of control experiments suggest that the chloride anions, remaining adsorbed on the catalyst surface under electrocatalytic conditions, can effectively inhibit the side reaction of hydrogen evolution and enhance the catalytic performance for CO2 reduction.

AB - Metallic silver (Ag) is known as an efficient electrocatalyst for the conversion of carbon dioxide (CO2) to carbon monoxide (CO) in aqueous or nonaqueous electrolytes. However, polycrystalline silver electrocatalysts require significant overpotentials in order to achieve high selectivity toward CO2 reduction, as compared to the side reaction of hydrogen evolution. Here we report a high-surface-area Ag nanocoral catalyst, fabricated by an oxidation-reduction method in the presence of chloride anions in an aqueous medium, for the electro-reduction of CO2 to CO with a current efficiency of 95% at the low overpotential of 0.37 V and the current density of 2 mA cm-2. A lower limit of TOF of 0.4 s-1 and TON > 8.8 × 104 (over 72 h) was estimated for the Ag nanocoral catalyst at an overpotential of 0.49 V. The Ag nanocoral catalyst demonstrated a 32-fold enhancement in surface-area-normalized activity, at an overpotential of 0.49 V, as compared to Ag foil. We found that, in addition to the effect on nanomorphology, the adsorbed chloride anions play a critical role in the observed enhanced activity and selectivity of the Ag nanocoral electrocatalyst toward CO2 reduction. Synchrotron X-ray photoelectron spectroscopy (XPS) studies along with a series of control experiments suggest that the chloride anions, remaining adsorbed on the catalyst surface under electrocatalytic conditions, can effectively inhibit the side reaction of hydrogen evolution and enhance the catalytic performance for CO2 reduction.

KW - carbon dioxide reduction

KW - chloride modification

KW - electrocatalysis

KW - high selectivity

KW - nanoporous Ag

UR - http://www.scopus.com/inward/record.url?scp=84941137345&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84941137345&partnerID=8YFLogxK

U2 - 10.1021/acscatal.5b01235

DO - 10.1021/acscatal.5b01235

M3 - Article

AN - SCOPUS:84941137345

VL - 5

SP - 5349

EP - 5356

JO - ACS Catalysis

JF - ACS Catalysis

SN - 2155-5435

IS - 9

ER -