CF2Cl2 Decomposition over Nanocrystalline MgO: Evidence for Long Induction Periods Full article
| Journal |
The Journal of Physical Chemistry B
ISSN: 1520-6106 , E-ISSN: 1520-5207 |
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| Output data | Year: 2005, Volume: 109, Number: 15, Pages: 6982-6989 Pages count : 8 DOI: 10.1021/jp047847s | ||||
| Tags | Chlorofluorocarbons; Composition; Decomposition; High resolution electron microscopy; Magnesium compounds; Sintering; Sorption; Transmission electron microscopy | ||||
| Authors |
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| Affiliations |
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Funding (4)
| 1 | Civilian Research and Development Foundation | RC1-2340-NO-02 |
| 2 | Президиум РАН | 8.23 |
| 3 | Council for Grants of the President of the Russian Federation | НШ-2120.2003.3 |
| 4 | Council for Grants of the President of the Russian Federation | НШ-1140.2003.3 |
Abstract:
CF2Cl2 has been found to react with nanoscale MgO at 325 °C and higher temperatures. In excess of the halocarbon, the reaction results in the formation of MgF2 as a predominant solid product, with CCl4, and CO2 formed as the main gaseous products. The kinetics of the process is characterized by a prolonged induction period, which is as long as 8.5 h at 325 °C. The length of the induction period decreases with temperature increase and becomes negligible at 500 °C. Complete CF2Cl2 mineralization has been achieved in an excess of MgO at 450 °C. Detailed HRTEM and EDX analysis has shown that the induction period involves the formation of small amounts of magnesium halides on the oxide surface and results in its reconstruction leading to initial oriental ordering of the nanocrystals followed by substantial changes in the bulk composition of the nanoparticles. The reaction proved to be structurally sensitive. It has been found that deep fluoridation is possible only for nanoscale MgO samples. The use of samples with lower surface areas results in lengthening of the induction period and decrease of the reaction depth. The MgO transformation to MgF2 has been found to result in a surface area decrease by more that an order of magnitude as a result of intense sintering of magnesium fluoride under the reaction conditions.
Cite:
Mishakov I.V.
, Zaikovskii V.I.
, Heroux D.S.
, Bedilo A.F.
, Chesnokov V.V.
, Volodin A.M.
, Martyanov I.N.
, Filimonova S.V.
, Parmon V.N.
, Klabunde K.J.
CF2Cl2 Decomposition over Nanocrystalline MgO: Evidence for Long Induction Periods
The Journal of Physical Chemistry B. 2005. V.109. N15. P.6982-6989. DOI: 10.1021/jp047847s WOS Scopus РИНЦ ANCAN PMID OpenAlex
CF2Cl2 Decomposition over Nanocrystalline MgO: Evidence for Long Induction Periods
The Journal of Physical Chemistry B. 2005. V.109. N15. P.6982-6989. DOI: 10.1021/jp047847s WOS Scopus РИНЦ ANCAN PMID OpenAlex
Dates:
| Submitted: | May 19, 2004 |
| Accepted: | Dec 28, 2004 |
| Published online: | Mar 30, 2005 |
| Published print: | Apr 1, 2005 |
Identifiers:
| Web of science: | WOS:000228419100015 |
| Scopus: | 2-s2.0-18144421912 |
| Elibrary: | 13493487 |
| Chemical Abstracts: | 2005:271639 |
| Chemical Abstracts (print): | 142:304311 |
| PMID: | 16851793 |
| OpenAlex: | W1968173644 |