| Autor: |
Makovsky, L. E., Pollack, S. S., Brown, F. R. |
| Zdroj: |
Nature; November 1980, Vol. 288 Issue: 5787 p154-155, 2p |
| Abstrakt: |
Deactivation of catalysts used to promote the liquefaction and desulphurization of coal is usually attributed to structural changes in the catalyst and the buildup of carbonaceous materials, minerals, iron and titanium. We discuss here the nature of the titanium which, though it is one of the major metals to deposit on and around catalysts, has never been characterized. The titanium deposited around a used catalyst removed from a fixed-bed reactor is very similar to one of the TiO2polymorphs (anatase) except that the c axis is 0.054 Å shorter. Two possible explanations for the origin of the anatase-like material are (1) that the titanium was originally organically bound in the coal, but it became oxidized during coal liquefaction, or (2) that small crystallites of the oxide existed in the coal and were simply concerned on and around the catalyst during liquefaction. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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