Structure of active phases during the course of electrocatalytic reactions

Journal Article · Thu Feb 10 04:00:00 EST 2000 · Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical

DOI:https://doi.org/10.1021/jp9917446· OSTI ID:20017302

Adzic, R R; Wang, J X

Structures of ordered adsorbates have been determined during the course of the electrocatalytic reduction of oxygen by using synchrotron surface X-ray scattering techniques. The origin of the catalytic action of Tl adlayers on O{sub 2} reduction on Au has been determined, and a possibility of measuring the adsorption configuration-specific activity in O{sub 2} reduction has been demonstrated in the reaction on Ag(100) with Br adlayer. On the Au(111) electrode surface, the oxidation/redeposition of Tl in catalyzing the four-electron oxygen reduction is revealed from the analysis of X-ray diffraction intensity as a function of the O{sub 2} reduction current for the (3 x {radical}3)-2TlBr adlayer. This indicates that the redox property of the metal adsorbates is responsible for the catalytic effect. On Ag(100) with the c(2 x 2)Br adlayer, the O{sub 2} reduction current resulting solely from adsorption in the end-on configuration through the 3-fold symmetry holes in the c(2 x 2) Br lattice is observed, showing the bridge adsorption may not be necessary for the four-electron O{sub 2} reduction on Ag at large overpotentials.

• Research Organization: Brookhaven National Lab., Upton, NY (US)
• Sponsoring Organization: US Department of Energy
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 20017302
• Journal Information: Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical, Journal Name: Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical Journal Issue: 5 Vol. 104; ISSN 1089-5647; ISSN JPCBFK
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
BROMINE
CRYSTAL STRUCTURE
ELECTROCATALYSTS
GOLD
OXYGEN
PHASE STUDIES
REDUCTION
SCATTERING
SILVER
THALLIUM
X-RAY SOURCES