Process for the preparation of acrylic and methacrylic acids
AssigneeNational Distillers and Chemical Corporation
InventorsJawad H. Murib, Charles E. Frank, Ben Seeskin
Life of this patent
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Abstract
The selective preparation of acrylic or methacrylic acids by a single step vapor phase oxidation of propylene or isobutylene, respectively, at temperatures up to 300.degree. C. in the presence of a catalyst containing palladium metal and phosphoric acid is improved by the use of a sulfur modifier.
Claims7
In a process for the preparation of acrylic or methacrylic acid by oxidizing propylene or isobutylene in the vapor phase with molecular oxygen in the presence of a catalyst composition consisting of phosphoric acid and a catalytically effective amount of palladium metal the improvement which comprises conducting the process in the presence of a sulfur catalyst modifier selected from the group consisting of elemental sulfur, H.sub.2 S, SO.sub.2, SO.sub.3, H.sub.2 SO.sub.3, H.sub.2 SO.sub.4, thioether, triphenylsulfonium salt of the formula (C.sub.6 H.sub.5).sub.3 SY where Y is Cl, 1/3 PO.sub.4, NO.sub.3, 1/2 SO.sub.4 or 1/2 SO.sub.3, diphenyl sulfoxide, dialkyl sulfoxide, metal sulfide, trialkyl thiophosphate of the formulae (RS).sub.3 P=O and (RS).sub.3 P=S wherein R is alkyl of 1-10 carbon atoms, and CS.sub.2.
Dependencies are inferred from the claim text.