Oxygen Reduction Reaction on Doped Lanthanum Chromate Perovskites
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Date
2024-01-19
Authors
Liu, Xinran
Journal Title
Journal ISSN
Volume Title
Publisher
University of Waterloo
Abstract
The oxygen reduction reaction (ORR) plays a pivotal role in fuel cell technology
and the generation of clean oxidizing agents. This reaction can proceed via two
distinct pathways. The complete ORR pathway involves reducing oxygen to water
through a four-electron transfer process. Alternatively, a two-electron transfer path-
way leads to the partial reduction of oxygen, yielding hydrogen peroxide (H2O2) as
the product. The perovskite CaSnO3 has demonstrated stability and selectivity in
electrochemically oxidizing H2O to H2O2. In a similar vein, other perovskite oxides
have demonstrated good selectivity in the complete ORR. Their catalytic perfor-
mance can be analyzed through microkinetic analysis and the application of scaling
relations. In this study, we explore a series of perovskites based on LaMO3, where
’M’ denotes a combination of Cr, Co, and Ni. Changes in the type and concentra-
tion of doping lead to contraction in the perovskite lattice, along with alterations in
B-O-B bond length and angle. These structural changes contribute to differences in
their catalytic performance towards the ORR. The inclusion of Co in the catalyst
tends to favor the four-electron ORR pathway, while the addition of Ni shows a
predilection for the two-electron pathway.
Description
Keywords
catalysts, electrochemistry, perovskite, oxygen reduction reaction