The oxygen reduction reaction on palladium with low metal loadings: The effects of chlorides on the stability and activity towards hydrogen peroxide

Author(s)

Fortunato, V, Guilherme ; Pizzutilo, Enrico ^[1] ; Cardoso, Eduardo S. F. ^[2] ; Lanza, V, Marcos R. ; Katsounaros, Ioannis ^[3] ; Freakley, Simon J. ^[4] ; Mayrhofer, Karl J. J. ^{[3, 5, 1]} ; Maia, Gilberto ^[2] ; Ledendecker, Marc ^{[6, 1]}

Affiliation

^[1] Fortunato, Guilherme, V, Max Planck Inst Eisenforsch GmbH, Dept Interface Chem & Surface Engn, Max Planck Str 1, D-40237 Dusseldorf - Germany

^[2] Fortunato, Guilherme, V, Univ Fed Mato Grosso do Sul, Inst Chem, Av Senador Filinto Muller 1555, BR-79074460 Campo Grande, MS - Brazil

^[3] Forschungszentrum Julich, Helmholtz Inst Erlangen Nurnberg Renewable Energy, Egerlandstr 3, D-91058 Erlangen - Germany

^[4] Univ Bath, Dept Chem, Bath BA2 7AY, Avon - England

^[5] Friedrich Alexander Univ Erlangen Nurnberg, Dept Chem & Biol Engn, Egerlandstr 3, D-91058 Erlangen - Germany

^[6] Tech Univ Darmstadt, Dept Tech Chem, Alarich Weiss Str 8, D-64287 Darmstadt - Germany

• Document type: Journal article
• Source: JOURNAL OF CATALYSIS; v. 389, p. 400-408, SEP 2020.
• Web of Science Citations: 5

Abstract

Hydrogen peroxide is considered one of the most important commodity chemicals worldwide but its main production method, the anthraquinone process, poses serious logistical, environmental and safety challenges. Electrocatalytic synthesis through the reduction of molecular oxygen is a promising H2O2 production route. However, the reduction of molecular oxygen is kinetically hindered and stable electrocatalysts with a high activity and selectivity towards the 2-electron transfer reaction are needed. In this work, we evaluated the influence of chloride on catalysts with low palladium loadings on the ORR selectivity towards H2O2. We report the factors and dynamics that influence H2O2 production and highlight synthesis strategies to obtain close to 100% selectivity. By probing the electrode surface after various degradation cycles, we evaluate the role of adsorbing species and the catalysts oxidation states on the hydrogen peroxide selectivity. We systematically modified the catalyst synthesis using different Pd-precursors that were reduced and supported on high surface area graphene nanoribbons. Identical location transmission electron microscopy was used to probe catalyst dynamics during reaction and the activities and selectivities were measured by a rotating ring disk electrode. We probe the potential boundary conditions that lead to catalyst degradation during accelerated stress tests and potentiostatic polarisation and demonstrate how the catalytically active surface can be revived after degradation. The obtained insights can be used as guideline for the development of active, selective and stable catalysts with low noble metal loadings. (C) 2020 Elsevier Inc. All rights reserved. (AU)

• FAPESP's process: 19/04421-7 - Production and characterization of metal-graphene or graphene oxide nanocomposites for the electrocatalytic production of hydrogen peroxide: Application to the degradation of endocrine disrupting chemicals by electrochemical advanced oxidation processes
• Grantee: Guilherme Vilalba Fortunato
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 17/10118-0 - Study and application of electrochemical technology for the analysis and degradation of endocrine interferents: materials, sensors, processes and scientific dissemination
• Grantee: Marcos Roberto de Vasconcelos Lanza
• Support Opportunities: Research Projects - Thematic Grants