TY - JOUR
T1 - Modification of CO2 reduction activity of nanostructured silver electrocatalysts by surface halide anions
AU - Hsieh, Yu Chi
AU - Betancourt, Luis E.
AU - Senanayake, Sanjaya D.
AU - Hu, Enyuan
AU - Zhang, Yu
AU - Xu, Wenqian
AU - Polyansky, Dmitry E.
N1 - Funding Information:
We thank Dr. G. Manbeck for help with preparation of this manuscript. This work was carried out at Brookhaven National Laboratory (BNL) and supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, & Biosciences, under Contract DE-SC0012704. S.D.S. is partially supported by a DOE Early Career Award. XPS and XRD measurements have been carried out at the National Synchrotron Light Source (U12A and X14A beamlines), a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Brookhaven National Laboratory under Contract DE-AC02-98CH10886. Electron microscopy and XRD studies have been conducted at the Center for Functional Nanomaterials, which is a U.S. DOE Office of Science Facility, at Brookhaven National Laboratory under Contract DE-SC0012704.
PY - 2019/1/28
Y1 - 2019/1/28
N2 - This paper describes the effect of halide anions (X = Cl, Br, I) immobilized on the surface of nanostructured silver electrocatalysts on the efficiency and the mechanism of CO2 reduction to CO in aqueous carbonate solutions. A simple oxidation-reduction cycle on Ag foil in the presence of halide anions produces high-surface-area nanostructured catalysts mainly composed of metallic Ag with a small amount of halide anions attached to the electrode surface (X-Ag) as demonstrated by XPS, XRD, and SEM studies. The activity of X-Ag electrocatalysts in 0.1 M NaHCO3 at pH 6.8 is significantly higher than that of Ag foil or Ag nanoparticles with comparable surface area and morphology. The activity enhancement is attributed to the formation of active catalytic sites, presumably Cl--Agn+ clusters on the surface of metallic Ag, as evidenced by XPS analysis. The activity of X-Ag catalysts is in the order Cl > Br > I, which is consistent with the proposed model of an active site. The Tafel analysis of electrochemical CO2 reduction points to the sensitivity of the mechanism of electrocatalysis on the nature of X.
AB - This paper describes the effect of halide anions (X = Cl, Br, I) immobilized on the surface of nanostructured silver electrocatalysts on the efficiency and the mechanism of CO2 reduction to CO in aqueous carbonate solutions. A simple oxidation-reduction cycle on Ag foil in the presence of halide anions produces high-surface-area nanostructured catalysts mainly composed of metallic Ag with a small amount of halide anions attached to the electrode surface (X-Ag) as demonstrated by XPS, XRD, and SEM studies. The activity of X-Ag electrocatalysts in 0.1 M NaHCO3 at pH 6.8 is significantly higher than that of Ag foil or Ag nanoparticles with comparable surface area and morphology. The activity enhancement is attributed to the formation of active catalytic sites, presumably Cl--Agn+ clusters on the surface of metallic Ag, as evidenced by XPS analysis. The activity of X-Ag catalysts is in the order Cl > Br > I, which is consistent with the proposed model of an active site. The Tafel analysis of electrochemical CO2 reduction points to the sensitivity of the mechanism of electrocatalysis on the nature of X.
KW - CO reduction
KW - Electrocatalysis
KW - Halide modifier
KW - Silver catalyst
KW - Silver cathode
UR - http://www.scopus.com/inward/record.url?scp=85063765691&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85063765691&partnerID=8YFLogxK
U2 - 10.1021/acsaem.8b01692
DO - 10.1021/acsaem.8b01692
M3 - Article
AN - SCOPUS:85063765691
VL - 2
SP - 102
EP - 109
JO - ACS Applied Energy Materials
JF - ACS Applied Energy Materials
SN - 2574-0962
IS - 1
ER -