Surface spectators and their role in relationships between activity and selectivity of the oxygen reduction reaction in acid environments

Author(s)

Ciapina, Eduardo G. ^{[1, 2, 3]} ; Lopes, Pietro P. ^[2] ; Subbaraman, Ram ^[2] ; Ticianelli, Edson A. ^[1] ; Stamenkovic, Vojislav ^[2] ; Strrncnik, Dusan ^[2] ; Markovic, Nenad M. ^[2]

Affiliation

^[1] Univ Sao Paulo, Inst Quim Sao Carlos, Sao Carlos, SP - Brazil

^[2] Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 - USA

^[3] UNESP Univ Estadual Paulista, Fac Engn, Guaratingueta, SP - Brazil

• Document type: Journal article
• Source: Electrochemistry Communications; v. 60, p. 30-33, NOV 2015.
• Web of Science Citations: 8

Abstract

We use the rotating ring disk (RRDE) method to study activity-selectivity relationships for the oxygen reduction reaction (ORR) on Pt(111) modified by various surface coverages of adsorbed CNad (Theta(CNad)). The results demonstrate that small variations in Theta(CNad) have dramatic effect on the ORR activity and peroxide production, resulting in ``volcano-like{''} dependence with an optimal surface coverage of Theta(CNad) = 0.3 ML These relationships can be simply explained by balancing electronic and ensemble effects of co-adsorbed CNad and adsorbed spectator species from the supporting electrolytes, without the need for intermediate adsorption energy arguments. Although this study has focused on the Pt(111)-CNad/H2SO4 interface, the results and insight gained here are invaluable for controlling another dimension in the properties of electrochemical interfaces. Published by Elsevier B.V. (AU)

• FAPESP's process: 13/16930-7 - Electrocatalysis V: electrocatalytic processes of chemical and electrical energy interconversion
• Grantee: Edson Antonio Ticianelli
• Support Opportunities: Research Projects - Thematic Grants