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Supplementary Information
Investigation of physicochemical properties and catalytic activity of
nanostructured Ce0.7M0.3O2–δ (M = Mn, Fe, Co) solid solutions for CO
oxidation
P VENKATASWAMYa, D JAMPAIAHa, C U ANIZb and BENJARAM M REDDYa,*
a
Inorganic and Physical Chemistry Division, CSIR–Indian Institute of Chemical Technology,
Uppal Road, Hyderabad 500 007, India
b
R&D Division, Sud–Chemie India Pvt. Limited, Binanipuram, Kerala 683 502, India
e-mail: [email protected]; [email protected]
List of contents:
Figure S1: Williamson–Holl (We–H) plots of pure CeO2 (C), Ce0.7Mn0.3O2–δ (CM),
Ce0.7Fe0.3O2–δ (CF), and Ce0.7Co0.3O2–δ (CC) samples calcined at 773 K.
Figure S2: Conversion of CO (%) versus temperature (K) over pure CeO2 (C) and MnOx
(Mn) samples along with Ce0.7Mn0.3O2–δ (CM) calcined at 773 K.
Table S1: Calculation of crystallite sizes using Debye-Scherrer equation for Ce0.7Mn0.3O2–δ
(CM), Ce0.7Fe0.3O2–δ (CF), and Ce0.7Co0.3O2–δ (CC) samples calcined at 773 K.
Table S2: The chemical composition of Ce0.7Mn0.3O2–δ (CM), Ce0.7Fe0.3O2–δ (CF), and
Ce0.7Co0.3O2–δ (CC) samples calcined at 773 K.
Table S3: Surface reduction temperatures and characteristic temperatures of CO oxidation
over different catalysts calcined at 773 K.
Figure S1. Williamson–Holl (We–H) plots of (a) pure CeO2 (C), (b) Ce0.7Mn0.3O2–δ (CM),
(c) Ce0.7Fe0.3O2–δ (CF), and (d) Ce0.7Co0.3O2–δ (CC) samples calcined at 773 K.
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Figure S2. Conversion of CO (%) versus temperature (K) over pure CeO2 (C) and MnOx
(Mn) samples along with Ce0.7Mn0.3O2–δ (CM) calcined at 773 K.
Normalized CO conversion (%)
100
90
T 90
80
70
390
60
50
602
627
T 50
40
30
20
CM
C
Mn
10
0
375
450
525
600
Temperature (K)
675
750
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Table S1. Calculation of crystallite sizes using Debye-Scherrer equation for Ce0.7Mn0.3O2–δ
(CM), Ce0.7Fe0.3O2–δ (CF), and Ce0.7Co0.3O2–δ (CC) samples calcined at 773 K.
The crystallite sizes of various samples calculated based on the Debye-Scherer equation.
Scherrer equation: D = K λ/βCosθ
Where,
D = Average crystallite size
λ = X-ray wavelength (0.15418 nm)
K = Particle shape factor (taken as 0.98)
β = Defined as the width at half maximum of the peak and θ the position (angle
in radians) of the peak.
For these calculations, the (111) peak of the typical fluorite structure of cerium oxides has
been used.
2θ
FWHM
D (nm)
C
28.56
0.01748
8.92
CM
28.75
0.02169
7.19
CF
28.92
0.02195
7.11
CC
28.78
0.01854
8.41
Sample
Table S2. The chemical composition of Ce0.7Mn0.3O2–δ (CM), Ce0.7Fe0.3O2–δ (CF), and
Ce0.7Co0.3O2–δ (CC) samples calcined at 773 K.
Sample
Nominal values
Actual
values
from
Fe
ICP-OES
Chemical formulae
analysis
Ce
Mn
Fe
Co
Ce
Mn
CM
0.7
0.3
−
−
0.69
0.31
CF
0.7
−
0.3
−
0.69
CC
0.7
−
0.3
0.69
Co
−
−
Ce0.69Mn0.31O2–δ
−
0.31
−
Ce0.69Fe0.31O2–δ
−
−
0.31
Ce0.69Co0.31O2–δ
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Table S3. Surface reduction temperatures and characteristic temperatures of CO oxidation
over different catalysts calcined at 773 K.
Sample
Surface reduction temperature (K)
T50 (K)
T90 (K)
C
758
602
625
CM
604
390
432
CF
723
440
463
CC
725
465
505