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Understanding the “Activation” of the Nanocluster [HxPMo12O40⊂H4Mo72Fe30(O2CMe)15O254(H2O)98-y(EtOH)y] for Low Temperature Growth of Carbon Nanotubes

Gibran L. Esquenazi, Andrew Barron Orcid Logo

Journal of Cluster Science, Volume: 29, Issue: 3, Pages: 431 - 441

Swansea University Author: Andrew Barron Orcid Logo

Abstract

The molecular nanocluster HxPMo12O40⊂H4Mo72Fe30(O2CMe)15O254(H2O)98-y(EtOH)y (FeMoC), was the first molecular catalyst precursor (pro-catalyst) that promised controlled growth of carbon nanotubes (CNTs); however, temperatures in excess of ~ 900 °C or the addition of excess iron were required as cata...

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Published in: Journal of Cluster Science
ISSN: 1040-7278 1572-8862
Published: 2018
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URI: https://cronfa.swan.ac.uk/Record/cronfa38908
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spelling 2018-05-01T16:27:34.6651788 v2 38908 2018-03-01 Understanding the “Activation” of the Nanocluster [HxPMo12O40⊂H4Mo72Fe30(O2CMe)15O254(H2O)98-y(EtOH)y] for Low Temperature Growth of Carbon Nanotubes 92e452f20936d688d36f91c78574241d 0000-0002-2018-8288 Andrew Barron Andrew Barron true false 2018-03-01 CHEG The molecular nanocluster HxPMo12O40⊂H4Mo72Fe30(O2CMe)15O254(H2O)98-y(EtOH)y (FeMoC), was the first molecular catalyst precursor (pro-catalyst) that promised controlled growth of carbon nanotubes (CNTs); however, temperatures in excess of ~ 900 °C or the addition of excess iron were required as catalyst promoters for CNT growth. To understand these disappointing results the “activation” of FeMoC for CNT growth was studied by systematic investigation of H2 gas concentration and growth temperature. The pathway for “activation” of FeMoC occurs through the sufficient reduction of both metal oxide components in the pro-catalyst. By ensuring pro-catalyst reduction prior to introduction of growth gases, we demonstrate for the first time, growth of CNTs at temperatures as low as 600 °C without the use of catalyst promoters using the single molecular precursor, FeMoC. To understand the role of catalyst promoters used in prior work, thermogravimetric analysis experiments were performed. The addition of an iron catalyst promoter is observed to play two key roles in the “activation” of FeMoC: (1) to replenish sublimated metal atoms, and (2) to reduce the reduction temperature required for reduction of FeMoC into an “active” catalyst. These results caution the conditions employed in many earlier studies for CNT growth, and create new possibilities for molecular pro-catalysts. Journal Article Journal of Cluster Science 29 3 431 441 1040-7278 1572-8862 Activation, Catalyst, Carbon nanotube (CNT), Polyoxometalate (POM) 31 12 2018 2018-12-31 10.1007/s10876-018-1348-8 COLLEGE NANME Chemical Engineering COLLEGE CODE CHEG Swansea University 2018-05-01T16:27:34.6651788 2018-03-01T08:33:45.7329484 Faculty of Science and Engineering School of Engineering and Applied Sciences - Chemical Engineering Gibran L. Esquenazi 1 Andrew Barron 0000-0002-2018-8288 2 0038908-01032018083816.pdf esquenazi2018(2).pdf 2018-03-01T08:38:16.0730000 Output 4068727 application/pdf Version of Record true 2018-03-01T00:00:00.0000000 true eng
title Understanding the “Activation” of the Nanocluster [HxPMo12O40⊂H4Mo72Fe30(O2CMe)15O254(H2O)98-y(EtOH)y] for Low Temperature Growth of Carbon Nanotubes
spellingShingle Understanding the “Activation” of the Nanocluster [HxPMo12O40⊂H4Mo72Fe30(O2CMe)15O254(H2O)98-y(EtOH)y] for Low Temperature Growth of Carbon Nanotubes
Andrew Barron
title_short Understanding the “Activation” of the Nanocluster [HxPMo12O40⊂H4Mo72Fe30(O2CMe)15O254(H2O)98-y(EtOH)y] for Low Temperature Growth of Carbon Nanotubes
title_full Understanding the “Activation” of the Nanocluster [HxPMo12O40⊂H4Mo72Fe30(O2CMe)15O254(H2O)98-y(EtOH)y] for Low Temperature Growth of Carbon Nanotubes
title_fullStr Understanding the “Activation” of the Nanocluster [HxPMo12O40⊂H4Mo72Fe30(O2CMe)15O254(H2O)98-y(EtOH)y] for Low Temperature Growth of Carbon Nanotubes
title_full_unstemmed Understanding the “Activation” of the Nanocluster [HxPMo12O40⊂H4Mo72Fe30(O2CMe)15O254(H2O)98-y(EtOH)y] for Low Temperature Growth of Carbon Nanotubes
title_sort Understanding the “Activation” of the Nanocluster [HxPMo12O40⊂H4Mo72Fe30(O2CMe)15O254(H2O)98-y(EtOH)y] for Low Temperature Growth of Carbon Nanotubes
author_id_str_mv 92e452f20936d688d36f91c78574241d
author_id_fullname_str_mv 92e452f20936d688d36f91c78574241d_***_Andrew Barron
author Andrew Barron
author2 Gibran L. Esquenazi
Andrew Barron
format Journal article
container_title Journal of Cluster Science
container_volume 29
container_issue 3
container_start_page 431
publishDate 2018
institution Swansea University
issn 1040-7278
1572-8862
doi_str_mv 10.1007/s10876-018-1348-8
college_str Faculty of Science and Engineering
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hierarchy_top_id facultyofscienceandengineering
hierarchy_top_title Faculty of Science and Engineering
hierarchy_parent_id facultyofscienceandengineering
hierarchy_parent_title Faculty of Science and Engineering
department_str School of Engineering and Applied Sciences - Chemical Engineering{{{_:::_}}}Faculty of Science and Engineering{{{_:::_}}}School of Engineering and Applied Sciences - Chemical Engineering
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description The molecular nanocluster HxPMo12O40⊂H4Mo72Fe30(O2CMe)15O254(H2O)98-y(EtOH)y (FeMoC), was the first molecular catalyst precursor (pro-catalyst) that promised controlled growth of carbon nanotubes (CNTs); however, temperatures in excess of ~ 900 °C or the addition of excess iron were required as catalyst promoters for CNT growth. To understand these disappointing results the “activation” of FeMoC for CNT growth was studied by systematic investigation of H2 gas concentration and growth temperature. The pathway for “activation” of FeMoC occurs through the sufficient reduction of both metal oxide components in the pro-catalyst. By ensuring pro-catalyst reduction prior to introduction of growth gases, we demonstrate for the first time, growth of CNTs at temperatures as low as 600 °C without the use of catalyst promoters using the single molecular precursor, FeMoC. To understand the role of catalyst promoters used in prior work, thermogravimetric analysis experiments were performed. The addition of an iron catalyst promoter is observed to play two key roles in the “activation” of FeMoC: (1) to replenish sublimated metal atoms, and (2) to reduce the reduction temperature required for reduction of FeMoC into an “active” catalyst. These results caution the conditions employed in many earlier studies for CNT growth, and create new possibilities for molecular pro-catalysts.
published_date 2018-12-31T03:49:22Z
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