Silver zirconium phosphate : preparation, characterization and catalytic properties of silver supported on zirconium phosphate
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| Other Authors: | , , , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1982.
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| Subjects: | |
| Online Access: | Link to ProQuest Copy Link to OAKTrust copy ProQuest, Abstract |
| Abstract: | The catalytic activity of metallic silver supported on zirconium phosphate has been examined in the reaction of ethylene oxidation in a flow reactor. The catalysts were prepared by ion-exchange of silver(I) ions in (alpha)-zirconium phosphate, followed by hydrogen reduction and ion-exchange of inert ions of interest into the ion-exchange sites. The mechanism of silver ion exchange on crystalline (alpha)-zirconium phosphate and the phases formed were determined. The exchange is nearly quantitative for silver acetate solutions but not for nitrate solutions because the pH of the acetate solutions is relatively high. A single exchanged phase of composition Zr(AgPO(,4))(,2)(.)H(,2)O occurs over the entire range of loadings. Heating the partially loaded exchanger to 200(DEGREES)C produces phases of approximate composition ZrAg(,0.22)H(,1.78)(PO(,4))(,2) and ZrAg(,0.75)H(,1.25)(PO(,4))(,2). The affinity of zirconium phosphate for silver ions is greater than for any alkali metal cations. The kinetics of the reduction of Ag('+) ions in (alpha)-zirconium phosphate by hydrogen and the formation of silver particles have been studied. The reaction rate is found to conform to an Elovich-type equation. The initial rate is to be directly proportional to the Ag('+) loading and to the surface area of the support but proportional to the half-power of the hydrogen pressure. The slow nucleation of silver particles is suggested to be responsible for the induction period. The average diameter of the silver particles is dependent on the Ag('+) loadings and on the surface area of the support... |
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| Item Description: | "Major subject: Chemistry." Typescript (photocopy). Vita. |
| Physical Description: | xvi, 179 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references (leaves 166-176). |