A method is described for producing a catalyst having a high raw material conversion rate and a high product selectivity, as well as an excellent yield of unsaturated carboxylic acid, the catalyst being used in a vapor-phase catalytic oxidation reaction for producing an unsaturated carboxylic acid such as acrylic acid or methacrolein from an unsaturated aldehyde such as acrolein or methacrolein. The method includes a molding process of molding a powder containing a catalyst component element to produce a catalyst precursor, where a sulfur-containing inorganic compound is added to the powder, and the powder is molded in the molding process.

A method is described for producing a catalyst having a high raw material conversion rate and a high product selectivity, as well as an excellent yield of unsaturated carboxylic acid, the catalyst being used in a vapor-phase catalytic oxidation reaction for producing an unsaturated carboxylic acid such as acrylic acid or methacrolein from an unsaturated aldehyde such as acrolein or methacrolein. The method includes a molding process of molding a powder containing a catalyst component element to produce a catalyst precursor, where a sulfur-containing inorganic compound is added to the powder, and the powder is molded in the molding process.

Catalyst compositions and methods of preparation comprising: preparing a promoter metal-molecular sieve catalyst composition comprising a promoter metal and a molecular sieve; and incorporating an iron salt into the promoter metal-molecular sieve catalyst composition.

Catalyst compositions and methods of preparation comprising: preparing a promoter metal-molecular sieve catalyst composition comprising a promoter metal and a molecular sieve; and incorporating an iron salt into the promoter metal-molecular sieve catalyst composition.

Provided is a thermally stable bisphenol composition whose increase in the Hazen color number is suppressed even under higher temperature conditions. A bisphenol composition including an aryl alkyl sulfide or a dialkyl disulfide at 0.1 ppb by mass to 1% by mass with respect to a bisphenol. A bisphenol composition including an aryl alkyl sulfide or a dialkyl disulfide at a predetermined ratio is thermally stable in terms of the Hazen color number, and shows no coloring problem under high temperature conditions. By using such a bisphenol composition, a polycarbonate resin having an excellent color tone can be produced.

Provided is a thermally stable bisphenol composition whose increase in the Hazen color number is suppressed even under higher temperature conditions. A bisphenol composition including an aryl alkyl sulfide or a dialkyl disulfide at 0.1 ppb by mass to 1% by mass with respect to a bisphenol. A bisphenol composition including an aryl alkyl sulfide or a dialkyl disulfide at a predetermined ratio is thermally stable in terms of the Hazen color number, and shows no coloring problem under high temperature conditions. By using such a bisphenol composition, a polycarbonate resin having an excellent color tone can be produced.

A process for synthesizing an azo compound by oxidation of a hydrogen compound in the presence of a catalyst and a compound of formula (I) is described in which R.sub.1, R.sub.2 and R.sub.3
(R.sub.1)(R.sub.2)C(PO.sub.3(R.sub.3).sub.2).sub.2  (I)
are as defined. The use of a compound of formula (I) as complexing agent for a catalyst is also described.

A process for synthesizing an azo compound by oxidation of a hydrogen compound in the presence of a catalyst and a compound of formula (I) is described in which R.sub.1, R.sub.2 and R.sub.3
(R.sub.1)(R.sub.2)C(PO.sub.3(R.sub.3).sub.2).sub.2  (I)
are as defined. The use of a compound of formula (I) as complexing agent for a catalyst is also described.

The present disclosure provides for methods for depolymerizing lignin to produce other useful products. For example, low molecular weight aromatic and aliphatic hydrocarbons (e.g., hydrocarbons having 8 to 20 carbon atoms (C8 to C20 hydrocarbons)) as well as oil products can be produced using methods of the present disclosure. The method can include treatment of the lignin using a catalyst composition, where the catalyst composition comprises a persulfate salt and a transition metal catalyst.

The present disclosure provides for methods for depolymerizing lignin to produce other useful products. For example, low molecular weight aromatic and aliphatic hydrocarbons (e.g., hydrocarbons having 8 to 20 carbon atoms (C8 to C20 hydrocarbons)) as well as oil products can be produced using methods of the present disclosure. The method can include treatment of the lignin using a catalyst composition, where the catalyst composition comprises a persulfate salt and a transition metal catalyst.