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Please use this identifier to cite or link to this item: http://repository.iitr.ac.in/handle/123456789/3860
Title: Cobalt doped CuO nanoparticles as a highly efficient heterogeneous catalyst for reduction of 4-nitrophenol to 4-aminophenol
Authors: Sharma A.
Dutta R.K.
Roychowdhury A.
Das D.
Goyal A.
Kapoor A.
Published in: Applied Catalysis A: General
Abstract: We present here a simple thermal route for synthesizing 5.1 wt% cobalt doped CuO nanoparticles (NPs) as the optimized composition of the best heterogeneous CuO catalyst for catalytic reduction of toxic 4-nitrophenol to industrially beneficial 4-aminophenol. The reduction is completed in merely 3 min in the presence of 8 mM NaBH4 as reducing agent. The optimized catalyst dose was 2 mg/L for converting 0.12 mM 4-nitrophenol and the corresponding rate constant (k) for reduction reaction was 43.8 × 10?3 s?1 per mg of catalyst. The catalytic reduction reaction was monitored by UV–vis spectroscopy method and by HPLC analysis. The mechanism is discussed in the light of hydride transfer phenomenon facilitated by large surface area and positive surface charge of the cobalt doped CuO nanoparticles. The cobalt doping resulted in: (a) increasing surface area due to decrease in particle size of the CuO NPs to 10 nm, measured by HRTEM; (b) improve stability of the cobalt doped CuO NPs. The cobalt dopant occupied the grain boundaries of CuO to reduce the particle size as derived from positron annihilation lifetime spectroscopy. The X-ray photoelectron spectroscopy analysis of unused catalyst and the spent catalyst revealed occurrence of Co2+ and Co3+ states at the surface. While the X-ray diffraction studies of spent catalyst confirmed the inhibition of reduction of the surface CuO to metallic copper in the presence of NaBH4, attributable to cobalt doping. It was concluded that cobalt doping led to stable and efficient CuO NPs as catalyst for reduction reaction. © 2017 Elsevier B.V.
Citation: Applied Catalysis A: General (2017), 543(): 257-265
URI: https://doi.org/10.1016/j.apcata.2017.06.037
http://repository.iitr.ac.in/handle/123456789/3860
Issue Date: 2017
Publisher: Elsevier B.V.
Keywords: 4-aminophenol
4-nitrophenol
Catalytic conversion
Cobalt doping
CuO nanoparticles
Positron annihilation lifetime spectroscopy
ISSN: 0926860X
Author Scopus IDs: 56555537300
47161194700
55604295800
56377535300
57197522024
57193984615
Author Affiliations: Sharma, A., Centre for Nanotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, India
Dutta, R.K., Centre for Nanotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, India, Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee, 247667, India
Roychowdhury, A., UGC-DAE Consortium for Scientific Research, Kolkata Centre, III/LB-8, Bidhannagar, Kolkata, 700098, India
Das, D., UGC-DAE Consortium for Scientific Research, Kolkata Centre, III/LB-8, Bidhannagar, Kolkata, 700098, India
Goyal, A., Solid State Physics Laboratory, Lucknow Road, Timarpur, New Delhi, 110054, India
Kapoor, A., Solid State Physics Laboratory, Lucknow Road, Timarpur, New Delhi, 110054, India
Funding Details: Aarti Sharma is thankful to Ministry of Human Resource Development (MHRD), Govt of India for awarding Senior Research Fellowship. R.K. Dutta is thankful to SERB, Department of Science and Technology, Government of India for sanctioning the Project No. DST/INT/AUS/P-52/2012. Authors also thank the instrumental facilities of the Institute Instrumentation Centre, IIT Roorkee.
Corresponding Author: Dutta, R.K.; Department of Chemistry, Indian Institute of Technology RoorkeeIndia; email: duttafcy@iitr.ac.in
Appears in Collections:Journal Publications [CY]

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