Work

Huge Instability of Pt/C Catalysts in Alkaline Medium

Year: 2015

Type: article

Abstract: The stability of carbon-supported electrocatalysts has been largely investigated in acidic electrolytes, but the literature is much scarcer regarding similar stability studies in alkaline medium. Herein, the degradation of Vulcan XC-72-supported platinum nanoparticles (noted Pt/C), a state-of-the-art proton exchange membrane fuel cell electrocatalyst, is investigated in alkaline medium by combining electrochemical measurements and identical location transmission electron microscopy; electrochemical surface area (ECSA) losses were bridged to electrocatalyst morphological changes. The results demonstrate that the degradation in 0.1 M NaOH at 25 °C is severe (60% of ECSA loss after only 150 cycles between 0.1 and 1.23 V vs RHE), which is about 3 times worse than in acidic media for this soft accelerated stress test. Severe carbon corrosion has been ruled out according to Raman spectroscopy and X-ray photoelectron spectroscopy measurements, and it seems that the chemistry of the carbon support (in particular, the interface (chemical bounding)) between the Pt nanoparticles and their carbon substrate does play a significant role in the observed degradations.

Source: ACS Catalysis

DOI: 10.1021/acscatal.5b01037

Authors: Anicet Zadick, Laetitia Dubau, Nicolas Sergent, Grégory Berthomé, Marian Chatenet

Institutions: Centre National de la Recherche Scientifique, Laboratoire d’Electrochimie et de Physico-chimie des Matériaux et des Interfaces, Université Grenoble Alpes, Science et Ingénierie des Matériaux et Procédés, Institut Universitaire de France

Language: English

Topic: Electrocatalysts for Energy Conversion

Subfield: Renewable Energy, Sustainability and the Environment

Field: Energy

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: green

Funders: Agence Nationale de la Recherche, Institut Universitaire de France