Abstract: An object of the present invention is to provide a process for stably producing a catalyst for methacrylic acid production exhibiting high activity and high performance. The process for producing a catalyst for methacrylic acid production of the invention is characterized in that the water content of the catalyst ingredient powder for use in molding, temperature and humidity of a molding step, humidity and temperature of a baking step are individually controlled in the case where molding is performed by a coating method using an Mo—V—P—Cu-based hetero polyacid as an active ingredient and water or an alcohol and/or an aqueous solution of an alcohol as a binder.

Abstract: An object of the present invention is to provide a process for stably producing a catalyst for methacrylic acid production exhibiting high activity and high performance. The process for producing a catalyst for methacrylic acid production of the invention is characterized in that the water content of the catalyst ingredient powder for use in molding, temperature and humidity of a molding step, humidity and temperature of a baking step are individually controlled in the case where molding is performed by a coating method using an Mo—V—P—Cu-based hetero polyacid as an active ingredient and water or an alcohol and/or an aqueous solution of an alcohol as a binder.

Abstract: The present invention concerns a method for producing acrolein and acrylic acid by carrying out vapor phase catalytic oxidation of propylene with molecular oxygen or a gas containing molecular oxygen using a oxidation catalysts comprising Mo, Bi and Fe as an essentially element and a fixed bed multitubular reactor, which comprisesa) using a plurality of supported catalysts having different activities, which was obtained, for example, by different calcination method in the production process of the supported catalysts,b) setting a catalyst layer in a reaction tube, which is formed by dividing it into plural portions in the tube axial direction, andc) arranging the aforementioned plural supported catalysts in such order that the activity becomes high toward the outlet from the inlet of the material gas in the reaction tube axial direction.

Abstract: A diamine platinum (II) complex represented by the general formula ##STR1## [wherein R.sub.1 and R.sub.2 are each a lower alkyl group; and two X's are each a halogen atom or jointly form a group represented by ##STR2## (wherein R.sub.3 and R.sub.4 are each a hydrogen atom or a lower alkyl group) or a group represented by ##STR3## (wherein m is 1 or 2)].

Abstract: A diamine platinum (II) complex represented by the general formula ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each a hydrogen atom or a lower alkyl group; and two X's are each a halogen atom or jointly form a group represented by ##STR2## wherein R.sub.5 and R.sub.6 are each a hydrogen atom or a lower alkyl group of a group represented by ##STR3## wherein m is 1 or 2.

Abstract: A diamine platinum (II) complex represented by the general formula ##STR1## [wherein R.sub.1 and R.sub.2 are each a lower alkyl group; and two X's are each a halogen atom or jointly form a group represented by ##STR2## (wherein R.sub.3 and R.sub.4 are each a hydrogen atom or a lower alkyl group) or a group represented by ##STR3## (wherein m is 1 or 2)].

Abstract: A diamine platinum (II) complex represented by the general formula ##STR1## [wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each a hydrogen atom or a lower alkyl group; and two X's are each a halogen atom or jointly form a group represented by ##STR2## (wherein R.sub.5 and R.sub.6 are each a hydrogen atom or a lower alkyl group) or a group represented by ##STR3## (wherein m is 1 or 2)].

Abstract: A diamine platinum (II) complex represented by the general formula ##STR1## [wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each a hydrogen atom or a lower alkyl group; and two X's are each a halogen atom or jointly form a group represented by ##STR2## (wherein R.sub.5 and R.sub.6 are each a hydrogen atom or a lower alkyl group) or a group represented by ##STR3## (wherein m is 1 or 2)].

Abstract: A diamine platinum (II) complex represented by the general formula ##STR1## [wherein R.sub.1 and R.sub.2 are each a lower alkyl group; and two X's are each a halogen atom or jointly form a group represented by ##STR2## (wherein R.sub.3 and R.sub.4 are each a hydrogen atom or a lower alkyl group) or a group represented by ##STR3## (wherein m is 1 or 2)].

Abstract: A diamine platinum (II) complex represented by the general formula ##STR1## [wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each a hydrogen atom or a lower alkyl group; and two X's are each a halogen atom or jointly form a group represented by ##STR2## (wherein R.sub.5 and R.sub.6 are each a hydrogen atom or a lower alkyl group) or a group represented by ##STR3## (wherein m is 1 or 2)].