Creation of defect Cu{sup +} sites in CuO-ZnO-Al{sub 2}O{sub 3} ternary catalyst
- Projects & Development India Ltd., Bihar (India); and others
In a previous communication, it was shown that the precipitate obtained from mixed nitrate solution of Cu, Zn, and Al is more or less monophasic in which Al{sup 3+} ions have been incorporated in the aurichalcite (Cu, Zn){sub 5}(CO{sub 3}){sub 2}(OH){sub 6} structure, causing appreciable distortion. In the present investigation, calcined Cu, Zn, and Al oxide catalyst has been studied with a view to find out to what extent the defect structure of the oxide is modified by the inclusion of Al{sup 3+} ion. The samples of Cu/Zn/Al oxide were prepared by coprecipitation from the mixed metal nitrate solution. The dry precipitate was calcined in air at 623 K for 5 h. The calcined oxide contained 30% CuO and O-15% Al{sub 2}O{sub 3} and 70-55% ZnO. The samples were marked A{sub 0}, A{sub 2}, A{sub 6}, A{sub 10}, and A{sub 15}, where the subscript indicates percentage of Al{sub 2}O{sub 3} by weight. A sample of Cu-Zn oxide was also prepared by mechanically mixing oxides of copper and zinc obtained by calcination of respective precipitates (prepared from nitrates using ammonium bicarbonate as before) in the ratio 30:70 by weight. X-ray diffraction studies indicate that both copper and zinc oxide are present in highly dispersed state, but free aluminum oxide could not be detected. A Varian X-band superheterodyne spectrometer was used for ESR measurements. In each case, an equal amount of the sample (about 100 mg) was taken, and all the measurements were carried out at room temperature.
- OSTI ID:
- 450707
- Journal Information:
- Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 1 Vol. 125; ISSN 0022-4596; ISSN JSSCBI
- Country of Publication:
- United States
- Language:
- English
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