Issue 24, 2016

Hydrothermal synthesis and characterization under dynamic conditions of cobalt oxide nanoparticles supported over magnesium oxide nano-plates

Abstract

A nano-catalyst comprised of oxidized Co NPs supported on MgO nano-plates was synthesized via a hydrothermal co-precipitation strategy and calcination in O2 and subsequently in H2 at 250 °C. Spectro-microscopy characterization was performed by scanning transmission electron microscopy, electron energy loss spectroscopy and scanning X-ray transmission microscopy. Surface measurements under H2 and H2 + CO atmospheres were obtained by ambient pressure X-ray photoelectron spectroscopy and in situ X-ray absorption spectroscopy in the 225–480 °C range. These measurements at the atomic and microscopic levels demonstrated that the oxidized Co nanoparticles uniformly decorated the MgO nano-plates. The surfaces are enriched with Co, and with a mixture of Co(OH)2 and CoO under H2 and H2 + CO atmospheres. Under a H2 atmosphere, the outermost surfaces were composed of (lattice) O2−, CO32− and OH. No inorganic carbonates were observed in the bulk. Chemisorbed CO, likely on the oxidized Co surfaces, was observed at the expense of O2− under 300 mTorr H2 + CO (2 : 1) at 225 °C. Gas phase CO2 was detected under 32 Torr H2 + CO (2 : 1) at 225 °C upon prolonged reaction time, and was attributed to a surface chemical reaction between O2− and chemisorbed CO. Furthermore, sp3 like carbon species were detected on the otherwise carbon free surface in H2 + CO, which remained on the surface under the subsequent reaction conditions. The formation of sp3 like hydrocarbons was ascribed to a surface catalytic reaction between the chemisorbed CO and OH as the apparent hydrogen source.

Graphical abstract: Hydrothermal synthesis and characterization under dynamic conditions of cobalt oxide nanoparticles supported over magnesium oxide nano-plates

Supplementary files

Article information

Article type
Paper
Submitted
15 Jan 2016
Accepted
03 Mas 2016
First published
07 Mas 2016

Dalton Trans., 2016,45, 9932-9941

Hydrothermal synthesis and characterization under dynamic conditions of cobalt oxide nanoparticles supported over magnesium oxide nano-plates

S. Alayoglu, D. J. Rosenberg and M. Ahmed, Dalton Trans., 2016, 45, 9932 DOI: 10.1039/C6DT00204H

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements