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Materials Science and Nanotechnology | Volume 2
May 21-22, 2018 | New York, USA
International Conference on
Nanoscience & Technology
T
he substitution of so-called critical elements, among
which Noble Metals (NM) and some Rare Earths (RE)
are included, has become a question of major concern to
reach the goal of sustainable development. In the particular
context of Heterogeneous Catalysis, the substitution of NM
by Transition, mostly 3d, Metals, is an issue that has already
received attention. In connection with this target, ABO
3
perovskite related oxides have been essayed as catalysts
in a number of reactions, most of them redox processes.
In particular, lanthanide based perovskites have been
extensively studied as catalysts in the CO oxidation reaction.
Total substitution of La by Ba fits perfectly with the actual
demands to replace critical RE. BaFeO
3
-d (0.2<d<0.4) depicts
a 6H perovskite hexagonal structural type with Fe both in
III and IV oxidation states and oxygen nonstoichiometry
accommodated by random distribution of anionic vacancies.
The decrease of the particle size dramatically decreases
the temperature of the reduction process of the sample.
Actually, under soft conditions (T≈ 200 °C/H
2
), nano-
BaFeO2.78 suffer an easy and reversible reduction process
that occurs by a different pathway than that described for
BaFeO
3
-δ bulk material. This material proved to be more
active than its lanthanide-based counterpart. The analysis of
the structural and chemical aspects of the reduction process
of nano-BaFeO2.78 makes possible to propose the role of the
oxygen deficiency responsible for the CO oxidation activity of
BaFeO
3
-δ.
Speaker Biography
Marina Parras-Vazquez, full professor at Inorganic Chemistry Department in
Complutense University of Madrid, currently works in the synthesis and structural/
microstructural characterizations of new functional inorganic materials. She is
co-author of more than 100 reviewed scientific publications and more than 100
communications to international conferences.
e:
mparras@quim.ucm.esNano size BaFeO3-d material: The role of oxygen non stoichiometry in the CO oxidation activity
Marina Parras
Universidad Complutense Madrid, Spain