Vol.:(0123456789) 1 3
Catalysis Letters
https://doi.org/10.1007/s10562-019-03014-z
Cr‑Doped CeO
2
Nanorods for CO Oxidation: Insights into Promotional
Efect of Cr on Structure and Catalytic Performance
Perala Venkataswamy
1
· Devaiah Damma
2
· Deshetti Jampaiah
3
· Deboshree Mukherjee
4
· Muga Vithal
1
·
Benjaram M. Reddy
4
Received: 25 July 2019 / Accepted: 24 October 2019
© Springer Science+Business Media, LLC, part of Springer Nature 2019
Abstract
Development of non-noble metal catalysts for oxidation of CO is an important subject for reducing the automotive emis-
sions. Recently, shape-controlled synthesis of CeO
2
has increasingly attracted the attention of researchers due to its size- and
morphology-dependent unique properties. Following this line of thinking, herein, we successfully report the synthesis of
Cr-doped CeO
2
(Ce
1−x
Cr
x
O
2−δ
; X = 0.05, 0.1, and 0.15) nanorods with various Cr contents by a facile hydrothermal method.
Structural, surface, optical, and redox properties of the Cr-doped CeO
2
nanorods were investigated by various techniques,
namely, ICP-OES, TEM-HRTEM, FE-SEM/EDX/EDS, XRD, BET, Raman, UV–vis DRS, PL, XPS, H
2
-TPR, and O
2
-TPD.
The catalytic performance was evaluated for CO oxidation. For comparison, the efciency of Cr
2
O
3
was also studied for CO
oxidation under identical conditions. As revealed by various characterization results, the chromium ions were doped into
the ceria lattice (formation of Ce–O–Cr solid solution), which enhanced the intrinsic properties such as oxygen vacancy
concentration and surface area. It was found that the Cr-doped CeO
2
nanorods show superior CO oxidation activity than the
pristine counterparts (CeO
2
nanorods and Cr
2
O
3
). The highest CO oxidation efciency was achieved with the light-of tem-
perature of T
50
= 261 °C, when the Cr doping amount was 10% (Ce
0.9
Cr
0.1
O
2−δ
). A high specifc surface area, more number
of surface oxygen vacancies, a high concentration of Ce
3+
, and enhanced oxygen reducibility of Ce
0.9
Cr
0.1
O
2−δ
nanorods
were found to be responsible for its superior catalytic performance. Further, the Ce
0.9
Cr
0.1
O
2−δ
nanorods exhibited a steady
CO conversion over a period of 55 h investigated. The obtained results are expected to have a signifcant impact on the use
of non-noble metal based Cr-doped CeO
2
nanorods in environmental applications.
Electronic supplementary material The online version of this
article (https://doi.org/10.1007/s10562-019-03014-z) contains
supplementary material, which is available to authorized users.
* Perala Venkataswamy
pvschemou07@gmail.com
* Benjaram M. Reddy
bmreddy@iict.res.in
1
Department of Chemistry, Osmania University,
Hyderabad 500 007, India
2
Chemical Engineering, College of Engineering and Applied
Science, University of Cincinnati, Cincinnati, OH 45221–
0012, USA
3
Centre for Advanced Materials and Industrial Chemistry
(CAMIC), School of Science, RMIT University, GPO BOX
2476, Melbourne, VIC 3001, Australia
4
Catalysis and Fine Chemicals Department, CSIR-Indian
Institute of Chemical Technology, Uppal Road,
Hyderabad 500 007, India