posted on 2020-03-16, 18:42authored byYun Sik Kang, Daeil Choi, Jinwon Cho, Hee-Young Park, Kug-Seung Lee, Minjeh Ahn, Injoon Jang, Taehyun Park, Hyung Chul Ham, Sung Jong Yoo
In this paper, we
report the preparation of a highly active and
durable ordered intermetallic PdFe catalyst supported on carbon black
for formic acid oxidation reaction (FAOR) by high-temperature heat
treatment under a reductive atmosphere. We found that the ordered
intermetallic PdFe catalyst exhibited considerably better catalytic
activity and durability toward FAOR than the disordered PdFe and pure
Pd catalysts because of the high alloying degree between Pd and Fe,
which induced a downshift of the Pd d-band center and structural modifications
that formed a superlattice crystalline structure with Pd surface segregation.
We analyzed the improved catalytic properties of the ordered intermetallic
PdFe catalyst through various electrochemical analyses such as cyclic
voltammetry, CO oxidation methods, chronoamperometry, physicochemical
analyses such as X-ray photoelectron spectroscopy, and synchrotron
radiation methods such as X-ray absorption spectroscopy. Density functional
theory calculation verified the improved FAOR activity of the ordered
intermetallic PdFe catalyst. In addition, a single cell based on the
ordered intermetallic PdFe catalyst was also fabricated and exhibited
enhanced cell performance compared to those based on the other catalysts.
To the best of our knowledge, this is the first study on the preparation
of an ordered intermetallic PdFe catalyst for FAOR with real single-cell
application in direct formic acid fuel cells (DFAFCs). We believe
that our results will be helpful for the development of highly active
and durable Pd alloy catalysts for FAOR and the commercialization
of DFAFC.