Mitsui Toatsu Chemicals, Incorporated

Jun Kitagawa

Kazunori Kawahara

Tadatoshi Honda

Masami Murakami

Nobuhiko Horiuchi

Shinji Takenaka

Yukihiro Yoshikawa

Tokio Nagayama

Kunihiro Yamada

Tooru Hihara

Hirofumi Io

A composite oxide catalyst represented by the general formula: Mo-V-P-X-Y (wherein X represents at least one element selected from the group consisting of Sb, Cu, Co, Bi and As; Y represents at least one element selected from the group consisting of K, Rb, Cs and Tl) and a method for preparing methacrylic acid through gas phase catalytic oxidation of methacrolein with molecular oxygen in the presence of the foregoing catalyst are herein disclosed. The catalyst exhibits excellent catalytic activity, selectivity to methacrylic acid, catalytic stability and lifetime.

Catalyst for oxidizing methacrolein and method for preparing methacrylic

A method for preparing acrolein or methacrolein comprises subjecting propylene, secondary propanol, isobutylene or tertiary butanol to gas phase catalytic oxidation with molecular oxygen in the presence of a catalyst represented by the following general formula (I):

Method for preparing acrolein or methacrolein

The catalytic activity of a chromium oxide-based catalyst used in the production of chlorine by oxidation of hydrogen chloride gas with an oxygen-containing gas is regenerated by impregnating it with an aqueous solution of chromic acid anhydride or of a chromium salt and then calcining the catalyst at a temperature not higher than 800.degree. C.

Chromium oxide catalyst impregnation regeneration method

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Yamaguchi, Japan

Jun Kitagawa