Banca de DEFESA: GUSTAVO KAIQUE DA SILVA GUILHERME

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : GUSTAVO KAIQUE DA SILVA GUILHERME
DATE: 30/05/2022
TIME: 09:00
LOCAL: Google Meet
TITLE:

Estudo das propriedades estruturais, magnéticas, e eletrocatalíticas de compósitos de Fe-W e Fe-Mo para aplicação na
reação de evolução de oxigênio

KEY WORDS:

Hidrogênio, OER, Nanocompositos, Tungstênio, Molibdênio

PAGES: 56
BIG AREA: Ciências Exatas e da Terra
AREA: Física
SUMMARY:

The world energy demand grows year after year and because of the environmental impact of fossil fuels consumption, it is
urgent the search for a sustainable energy source. Hydrogen is a great candidate for this post, but his large-scale production still
faces some adversities. The cleanest way to produce this fuel is from the water electrolysis, which occurs through two half-
reactions, the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). The last one has slower kinetics,
which makes the total process not efficient. Thus, it is important to chose the right catalyst, however, nowadays the frequently
used cayalyst are based on rare and consequently more expensive materials, such as Pt and Ru. In this context, it is necessary
to search for catalysts of cheaper materials. Therefore, this work is dedicated to the synthesis and analysis of the physical
and electrochemical properties of Fe-W and Fe-Mo nanocomposites for application as OER catalyst. The nanocomposites were
produced by the sol-gel method, their structural characterizations were performed through X-ray difraction (XRD), their
magnetic properties studied by vibrating-sample magnetometry (VSM) and by Mössbauer spectroscopy (MS), and their
electrochemical specicities were based on linear scan voltammetry (LSV), electrochemically active area (ECSA) and
electrochemical impedance spectroscopy (EIS) measurements. Thus, for the system Fe-W, a nanocomposite containing two
distinct phases was obtained, Fe and Fe6W6C, and for the system Fe-Mo a composite that has the metals Fe, Mo and possibly
a non-homogeneous alloy of these two metals. The magnetic characterizations pointed to soft ferromagnetic materials, with
low remanent and coercive elds. On the other hand, the electrochemical measurements showed to be promising because both
composites presented overpotential values classied as ideal and very close to RuO2 in electrolysis in alkaline medium.

BANKING MEMBERS:
Externo à Instituição - ANDREA PAESANO JÚNIOR - UEM
Interno - 350830 - JOSE HUMBERTO DE ARAUJO
Presidente - 1674707 - MARCO ANTONIO MORALES TORRES