10.1021/acscatal.5b01281.s001
Alessandro Minguzzi
Alessandro
Minguzzi
Cristina Locatelli
Cristina
Locatelli
Ottavio Lugaresi
Ottavio
Lugaresi
Elisabetta Achilli
Elisabetta
Achilli
Giuseppe Cappelletti
Giuseppe
Cappelletti
Marco Scavini
Marco
Scavini
Mauro Coduri
Mauro
Coduri
Paolo Masala
Paolo
Masala
Benedetta Sacchi
Benedetta
Sacchi
Alberto Vertova
Alberto
Vertova
Paolo Ghigna
Paolo
Ghigna
Sandra Rondinini
Sandra
Rondinini
Easy Accommodation of Different Oxidation States in
Iridium Oxide Nanoparticles with Different Hydration Degree as Water
Oxidation Electrocatalysts
American Chemical Society
2015
Different Hydration Degree
XRPD
Iridium Oxide Nanoparticles
IrOx
IrO 2 shell
HR
pair distribution function
Water Oxidation ElectrocatalystsIn
material
synchrotron radiation techniques
TEM
operando XAS experiments
Different Oxidation States
PDF
transmission electron microscopy
Ir core
2015-09-04 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Easy_Accommodation_of_Different_Oxidation_States_in_Iridium_Oxide_Nanoparticles_with_Different_Hydration_Degree_as_Water_Oxidation_Electrocatalysts/2134570
In
this paper, we present a comprehensive study on low hydration Ir/IrO<sub>2</sub> electrodes, made of an Ir core and an IrO<sub>2</sub> shell,
that are designed and synthesized with an innovative, green approach,
in order to have a higher surface/bulk ratio of Ir–O active
centers. Three materials with different hydration degrees have been
deeply investigated in terms of structure and microstructure by means
of transmission electron microscopy (TEM) and synchrotron radiation
techniques such as high-resolution (HR) and pair distribution function
(PDF) quality X-ray powder diffraction (XRPD), X-ray absorption spectroscopy
(XAS), and for what concerns their electrochemical properties by means
of cyclic voltammetry and steady-state <i>I</i>/<i>E</i> curves. The activity of these materials is compared and
discussed in the light of our most recent results on hydrous IrO<sub><i>x</i></sub>. The main conclusion of this study is that the Ir core is noninteracting
with the IrO<sub><i>x</i></sub> shell, the latter being
able to easily accommodate Ir in different oxidation states, as previously
suggested for the hydrated form, thus explaining the activity as electrocatalysts.
In addition, in operando XAS experiments assessed that the catalytic
cycle involves Ir(III) and (V), as previously established for the
highly hydrated IrO<sub><i>x</i></sub> material.