Pt-supported
La1–x
Sr
x
CoO3 and Pt-doped La1–x
Sr
x
CoO3 are
synthesized using chemical reduction and solution combustion method,
respectively. Chemical reduction is carried out using formaldehyde
as a reducing agent giving Pt-supported La1–x
Sr
x
CoO3. Solution combustion
method is used to prepare Pt-doped La1–x
Sr
x
CoO3. Detailed characterization
using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS),
Brunauer–Emmett–Teller (BET) surface area measurement,
and transmission electron microscopy (TEM) is carried out to distinguish
the Pt-supported and Pt-doped compounds in terms of their morphology
and Pt oxidations states. TEM results indeed show the differences
in their morphology. Further, electrochemical measurements are performed
in neutral medium to differentiate their electrochemical activity.
Cyclic voltammetry (CV) shows noticeable differences between Pt-supported
La1–x
Sr
x
CoO3 and Pt-doped La1–x
Sr
x
CoO3. Importantly, our
results show that Pt4+ in doped compound has poor to zero
electrocatalytic activity toward formic acid and methanol electro-oxidation
in comparison to Pt0 in supported compound. This study
shows that metallic Pt in zero oxidation state is a superior catalyst
to Pt in +4 oxidation state.