Catalyst continued zirconium oxide

Zirconium tetrafluoride [7783-64-4] is used in some fluoride-based glasses. These glasses are the first chemically and mechanically stable bulk glasses to have continuous high transparency from the near uv to the mid-k (0.3—6 -lm) (117—118). Zirconium oxide and tetrachloride have use as catalysts (119), and zirconium sulfate is used in preparing a nickel catalyst for the hydrogenation of vegetable oil. Zirconium 2-ethyIhexanoate [22464-99-9] is used with cobalt driers to replace lead compounds as driers in oil-based and alkyd paints (see Driers and metallic soaps). 

Russian workers have continued their studies on the production of alkyl-pyrrolizidines from furan derivatives by catalytic dehydration. The original catalyst used was thorium oxide on alumina, but improved yields were obtained with zirconium oxide on alumina [Eq. (5)]. In the formation of... 

Biomimetic oxidations of alcohols and amines to carbonyl compounds continue to attract attention. Whilst methods are not yet of significant synthetic value, advances have been made in the development of oxidation catalysts. The isoalloxazine (1), when complexed with zirconium(iv), acts as an efficient catalyst for the oxidation of alcohols by oxygen, and the pyrimidopteridines (2) show high autorecycling efficiency in the oxidation of cyclopentanol. The deazatoxoflavin derivatives (3) oxidize primary amines to imines with high turnover of the catalyst. Subsequent hydrolysis liberates the carbonyl compound. 

Dehydrogenation activities of the oxides of selenium and tellurium were observed by the pulse technique.Thus, the zirconium oxides which are loaded with selenic acid or telluric acid and calcined in air can dehydrogenate 2-propanol to acetone and hexane to benzene.In a typical reaction of 2-propanol, the conversion into acetone decreases continuously after the third pulse, probably owing to a decrease in the amount of oxygen on the catalyst surface. Poisoning experiments with injection of CO2, H2O or butylamine at 523 K before reaction had no effect on the yield of acetone. Thus this dehydrogenation process appears to be an oxidative dehydrogenation. No studies on the acidic or basic character of oxides of selenium and tellurium oxides have been reported. 

Dialkylaminoethyl acryhc esters are readily prepared by transesterification of the corresponding dialkylaminoethanol (102,103). Catalysts include strong acids and tetraalkyl titanates for higher alkyl esters and titanates, sodium phenoxides, magnesium alkoxides, and dialkyitin oxides, as well as titanium and zirconium chelates, for the preparation of functional esters. Because of loss of catalyst activity during the reaction, incremental or continuous additions may be required to maintain an adequate reaction rate. 

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