Chiral-selective CoSO4/SiO2 catalyst for (9,8) single-walled carbon nanotube growth
Electronic and optical properties of single-walled carbon nanotubes (SWCNTs) correlate with their chiral structures. Many applications need chirally pure SWCNTs that current synthesis methods cannot produce. Here, we show a sulfate-promoted CoSO4/SiO2 catalyst, which selectively grows large-diameter...
| Main Authors: | , , , , , , |
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| Format: | Journal Article |
| Language: | English |
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2013
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| Online Access: | https://hdl.handle.net/10356/99606 http://hdl.handle.net/10220/17750 |
| _version_ | 1811696436288421888 |
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| author | Wang, Hong Wei, Li Ren, Fang Wang, Qiang Pfefferle, Lisa D. Haller, Gary L. Chen, Yuan |
| author2 | School of Chemical and Biomedical Engineering |
| author_facet | School of Chemical and Biomedical Engineering Wang, Hong Wei, Li Ren, Fang Wang, Qiang Pfefferle, Lisa D. Haller, Gary L. Chen, Yuan |
| author_sort | Wang, Hong |
| collection | NTU |
| description | Electronic and optical properties of single-walled carbon nanotubes (SWCNTs) correlate with their chiral structures. Many applications need chirally pure SWCNTs that current synthesis methods cannot produce. Here, we show a sulfate-promoted CoSO4/SiO2 catalyst, which selectively grows large-diameter (9,8) nanotubes at 1.17 nm with 51.7% abundance among semiconducting tubes and 33.5% over all tube species. After reduction in H2 at 540 °C, the catalyst containing 1 wt % Co has a carbon yield of 3.8 wt %, in which more than 90% is SWCNT. As compared to other Co catalysts used for SWCNT growth, the CoSO4/SiO2 catalyst is unique with a narrow Co reduction window under H2 centered at 470 °C, which can be attributed to the reduction of highly dispersed CoSO4. X-ray absorption spectroscopy (XAS) results suggested the formation of Co particles with an average size of 1.23 nm, which matches the diameter of (9,8) tubes. Density functional theory study indicated that the diameter of structurally stable pure Co particles is scattered, matching the most abundant chiral tubes, such as (6,5) and (9,8). Moreover, the formation of such large Co particles on the CoSO4/SiO2 catalyst depends on sulfur in the catalyst. XAS results showed that sulfur content in the catalyst changes after catalyst reduction at different conditions, which correlates with the change in (n,m) selectivity observed. We proposed that the potential roles of sulfur could be limiting the aggregation of Co atoms and/or forming Co–S compounds, which enables the chiral selectivity toward (9,8) tubes. This work demonstrates that catalysts promoted with sulfur compounds have potentials to be further developed for chiral-selective growth of SWCNTs. |
| first_indexed | 2024-10-01T07:39:20Z |
| format | Journal Article |
| id | ntu-10356/99606 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T07:39:20Z |
| publishDate | 2013 |
| record_format | dspace |
| spelling | ntu-10356/996062020-03-07T11:40:19Z Chiral-selective CoSO4/SiO2 catalyst for (9,8) single-walled carbon nanotube growth Wang, Hong Wei, Li Ren, Fang Wang, Qiang Pfefferle, Lisa D. Haller, Gary L. Chen, Yuan School of Chemical and Biomedical Engineering DRNTU::Engineering::Chemical engineering Electronic and optical properties of single-walled carbon nanotubes (SWCNTs) correlate with their chiral structures. Many applications need chirally pure SWCNTs that current synthesis methods cannot produce. Here, we show a sulfate-promoted CoSO4/SiO2 catalyst, which selectively grows large-diameter (9,8) nanotubes at 1.17 nm with 51.7% abundance among semiconducting tubes and 33.5% over all tube species. After reduction in H2 at 540 °C, the catalyst containing 1 wt % Co has a carbon yield of 3.8 wt %, in which more than 90% is SWCNT. As compared to other Co catalysts used for SWCNT growth, the CoSO4/SiO2 catalyst is unique with a narrow Co reduction window under H2 centered at 470 °C, which can be attributed to the reduction of highly dispersed CoSO4. X-ray absorption spectroscopy (XAS) results suggested the formation of Co particles with an average size of 1.23 nm, which matches the diameter of (9,8) tubes. Density functional theory study indicated that the diameter of structurally stable pure Co particles is scattered, matching the most abundant chiral tubes, such as (6,5) and (9,8). Moreover, the formation of such large Co particles on the CoSO4/SiO2 catalyst depends on sulfur in the catalyst. XAS results showed that sulfur content in the catalyst changes after catalyst reduction at different conditions, which correlates with the change in (n,m) selectivity observed. We proposed that the potential roles of sulfur could be limiting the aggregation of Co atoms and/or forming Co–S compounds, which enables the chiral selectivity toward (9,8) tubes. This work demonstrates that catalysts promoted with sulfur compounds have potentials to be further developed for chiral-selective growth of SWCNTs. 2013-11-15T08:05:59Z 2019-12-06T20:09:28Z 2013-11-15T08:05:59Z 2019-12-06T20:09:28Z 2013 2013 Journal Article Wang, H., Wei, L., Ren, F., Wang, Q., Pfefferle, L. D., Haller, G. L., et al. (2013). Chiral-selective CoSO 4 /SiO 2 catalyst for (9,8) single-walled carbon nanotube growth . ACS nano, 7(1), 614-626. https://hdl.handle.net/10356/99606 http://hdl.handle.net/10220/17750 10.1021/nn3047633 en ACS nano |
| spellingShingle | DRNTU::Engineering::Chemical engineering Wang, Hong Wei, Li Ren, Fang Wang, Qiang Pfefferle, Lisa D. Haller, Gary L. Chen, Yuan Chiral-selective CoSO4/SiO2 catalyst for (9,8) single-walled carbon nanotube growth |
| title | Chiral-selective CoSO4/SiO2 catalyst for (9,8) single-walled carbon nanotube growth |
| title_full | Chiral-selective CoSO4/SiO2 catalyst for (9,8) single-walled carbon nanotube growth |
| title_fullStr | Chiral-selective CoSO4/SiO2 catalyst for (9,8) single-walled carbon nanotube growth |
| title_full_unstemmed | Chiral-selective CoSO4/SiO2 catalyst for (9,8) single-walled carbon nanotube growth |
| title_short | Chiral-selective CoSO4/SiO2 catalyst for (9,8) single-walled carbon nanotube growth |
| title_sort | chiral selective coso4 sio2 catalyst for 9 8 single walled carbon nanotube growth |
| topic | DRNTU::Engineering::Chemical engineering |
| url | https://hdl.handle.net/10356/99606 http://hdl.handle.net/10220/17750 |
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