Abstract

Electrodeposition and ageing under oxygen reduction reaction (ORR) of Mn-X/PPy (X=Co, Mg, Ni; PPy=polypyrrole) and Mn-Ag/G (G=graphene) composite electrocatalysts have been studied by quasi-in-situ soft X-ray absorption and fluorescence microspectroscopy. The fabricated materials exhibit micro-grained morphologies in which Mn is present mainly as Mn2+, accompanied by combinations of Co0/Co2+ and Ni0/Ni2+. Ageing leads to the formation of progressively larger mesoscopic aggregates. Initial ageing yields more active Mn3+ and Mn4+, in agreement with an improved ORR behaviour. Prolonged ageing causes the loss of Mn3+ and Mn4+ from the surface, in correlation with a degradation of the ORR response. In the investigated ageing period, Mn-Mg/PPy exhibits the best durability, with about half of the catalyst grains still showing the presence of Mn3+/Mn4+, while the others consist mainly of Mn2+. In Mn-Ni/PPy, the Ni2+ content tends to increase with ageing whereas Co3+ forms in the Mn-Co/PPy composites.

Autore Pugliese

• Bocchetta Patrizia , Mele Claudio , Bozzini Benedetto

Tutti gli autori

• Bozzini B. , Bocchetta P. , Gianoncelli A. , Mele C. , Kiskinova M.

Titolo volume/Rivista

CHEMELECTROCHEM

Anno di pubblicazione

2015

ISSN

2196-0216

ISBN

Non Disponibile

Numero di citazioni Wos

8

Ultimo Aggiornamento Citazioni

28/04/2018

Numero di citazioni Scopus

8

Ultimo Aggiornamento Citazioni

28/04/2018

Settori ERC

Non Disponibile

Codici ASJC

Non Disponibile