The purpose of the present invention is to provide a method for synthesizing ammonia and an apparatus for the method. The method for synthesizing ammonia according to the present invention comprises: a step of melting a metal containing at least an alkali metal; and a step of supplying a hydrogen gas and a nitrogen gas to the molten metal.

The invention discloses a catalyst comprising a silica support, a modifier metal and a catalytic alkali metal. The silica support has a multimodal pore size distribution comprising a mesoporous pore size distribution having an average pore size in the range 2 to 50 nm and a pore volume of said mesopores of at least 0.1 cm.sup.3/g, and a macroporous pore size distribution having an average pore size of more than 50 nm and a pore volume of said macropores of at least 0.1 cm.sup.3/g. The level of catalytic alkali metal on the silica support is at least 2 mol %. The modifier metal is selected from Mg, B, Al, Ti, Zr and Hf. The invention also discloses a method of producing the catalyst, a method of producing an ethylenically unsaturated carboxylic acid or ester in the presence of the catalyst, and a process for preparing an ethylenically unsaturated acid or ester in the presence of the catalyst.

The invention discloses a catalyst comprising a silica support, a modifier metal and a catalytic alkali metal. The silica support has a multimodal pore size distribution comprising a mesoporous pore size distribution having an average pore size in the range 2 to 50 nm and a pore volume of said mesopores of at least 0.1 cm.sup.3/g, and a macroporous pore size distribution having an average pore size of more than 50 nm and a pore volume of said macropores of at least 0.1 cm.sup.3/g. The level of catalytic alkali metal on the silica support is at least 2 mol %. The modifier metal is selected from Mg, B, Al, Ti, Zr and Hf. The invention also discloses a method of producing the catalyst, a method of producing an ethylenically unsaturated carboxylic acid or ester in the presence of the catalyst, and a process for preparing an ethylenically unsaturated acid or ester in the presence of the catalyst.

A catalyst for catalytic oxidation of furfural to prepare maleic acid is composed of a carbon nitride doped with a potassium salt. A method for preparing the catalyst includes mixing the potassium salt, a precursor of the carbon nitride and a solvent to obtain a mixture, and drying and calcining the mixture to obtain the catalyst. A use of the catalyst in catalytic oxidation of furfural to prepare maleic acid, wherein the maleic acid is prepared by the step of oxidizing furfural in a solvent in the presence of the catalyst. The invention has the advantages that by using the method provided by the invention to prepare maleic acid, the conversion rate of furfural can be 99% or more and the yield of maleic acid can be up to 70.40%.

A catalyst for catalytic oxidation of furfural to prepare maleic acid is composed of a carbon nitride doped with a potassium salt. A method for preparing the catalyst includes mixing the potassium salt, a precursor of the carbon nitride and a solvent to obtain a mixture, and drying and calcining the mixture to obtain the catalyst. A use of the catalyst in catalytic oxidation of furfural to prepare maleic acid, wherein the maleic acid is prepared by the step of oxidizing furfural in a solvent in the presence of the catalyst. The invention has the advantages that by using the method provided by the invention to prepare maleic acid, the conversion rate of furfural can be 99% or more and the yield of maleic acid can be up to 70.40%.

Synthesis of silanes with more than three silicon atoms are disclosed (i.e., Si.sub.nH.sub.(2n+2) with n=4-100). More particularly, the disclosed synthesis methods tune and optimize the isomer ratio by selection of process parameters such as temperature, residence time, and the relative amount of starting compounds, as well as selection of proper catalyst. The disclosed synthesis methods allow facile preparation of silanes containing more than three silicon atoms and particularly, the silanes containing preferably one major isomer. The pure isomers and isomer enriched mixtures are prepared by catalytic transformation of silane (SiH.sub.4), disilane (Si.sub.2H.sub.6), trisilane (Si.sub.3H.sub.8), and mixtures thereof.

Synthesis of silanes with more than three silicon atoms are disclosed (i.e., Si.sub.nH.sub.(2n+2) with n=4-100). More particularly, the disclosed synthesis methods tune and optimize the isomer ratio by selection of process parameters such as temperature, residence time, and the relative amount of starting compounds, as well as selection of proper catalyst. The disclosed synthesis methods allow facile preparation of silanes containing more than three silicon atoms and particularly, the silanes containing preferably one major isomer. The pure isomers and isomer enriched mixtures are prepared by catalytic transformation of silane (SiH.sub.4), disilane (Si.sub.2H.sub.6), trisilane (Si.sub.3H.sub.8), and mixtures thereof.

A method for producing methyldichlorophosphane, the method including: allowing methane and phosphorus trichloride to react in the presence of an additive using a metal compound, or a metal compound carried on a carrier, or both thereof.

A catalyst including a modified silica support having a titanium modifier metal, and a catalytic metal on the modified silica support. A proportion of the modifier metal is present in the form of mononuclear titanium moieties or is derived from a mononuclear titanium cation source at the commencement of modification. The invention also discloses a corresponding modified silica support, a method of producing the catalyst or the modified silica support, and a process for preparing an ethylenically unsaturated acid or ester in the presence of the catalyst.

A method for producing methyldichlorophosphane, the method including: allowing methane and phosphorus trichloride to react in the presence of an additive using a metal compound, or a metal compound carried on a carrier, or both thereof.