Publicou 12 edições por ano
ISSN Imprimir: 1091-028X
ISSN On-line: 1934-0508
Indexed in
Coking of a Porous Catalyst and Its Inhibiting by Siliconiting Modification
RESUMO
In order to inhibit the coke deposition on the surface of ZSM-5, used as the catalyst for oxidation of benzene to phenol (BTOP) by nitrous oxide, the method of chemical surface deposition of silicon is chosen to modify the surface of ZSM-5. In this paper, the effect of modification condition on the micropore structure and catalyst activity was studied. The porous catalyst was characterized by XRF, EPMA, TEM, XRD, N2 adsorption at −196° C, and pyridine adsorption-infrared techniques. The results show that the uniform SiO2 membrane can be formed on an external surface of the ZSM-5 crystal under moderate modification conditions. The SiO2 membrane covers the acid centers on ZSM-5 external surface, so ZSM-5 external surface coking is inhibited and the pore blockage is avoided or decreased. At the same time, the SiO2 membrane does not change the acid centers located in pores so that the catalyst activity and stability can be improved efficiently. The optimal siliconiting conditions were determined by experiments. Compared with the samples without siliconiting treatment, the samples treated under the optimal conditions can increase the productivity of phenol by 14% for 3 h reaction time and by 41% for 6 h reaction time, respectively.
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Charlton Brian, Fisher Andy S., Goodall Phill S., Hinds Michael W., Lancaster Steve, Salisbury Malcolm, Atomic spectrometry update. Industrial analysis: metals, chemicals and advanced materials, Journal of Analytical Atomic Spectrometry, 22, 12, 2007. Crossref