Nanowires useful as heterogeneous catalysts are provided. The nanowire catalysts are useful in a variety of catalytic reactions, for example, the oxidative coupling of methane to C2 hydrocarbons. Related methods for use and manufacture of the same are also disclosed.

To provide magnesium oxide which is excellent in hydration resistance and hardly causes volume expansion due to hydration and the like, a resin composition containing the same, and a method for producing the magnesium oxide powder.

Magnesium oxide powder having a coating layer mainly comprising basic magnesium carbonate in the surface layer, when the amounts of substances of water vapor and carbon dioxide among the gas generated by thermal decomposition at 50 to 500 C. are respectively designated as m-H.sub.2O and m-CO.sub.2, in a heating evolved gas analysis (EGA-MS) method, the molar fraction represented by m-CO.sub.2/(m-H.sub.2O+m-CO.sub.2) being within the range of 0.3 to 0.6.

The invention is referred to chemical technology, namely to active high-purity magnesium oxide and its production method.

Active high-purity magnesium oxide, including the surface treated one, has BET specific surface area from 70 to 200 m.sup.2/g, average particle size (d50) determined by laser diffraction method not more than 10 microns, iodine activity in the range from 70 to 200 mg J/g MgO, citric activity not more than 40 s, pore volume in the range from 3.210.sup.2 cm.sup.3/g to 10.210.sup.2 cm.sup.3/g, diameter of 10% of the particles not more than 2 microns, diameter of 90% of the particles not more than 30 microns, mass fraction of residue on the 150 micron sieve not more than 1%, mass fraction of residue on the 45 micron sieve not more than 2%, mass fraction of chlorides not more than 0.1%, mass fraction of calcium not more than 0.1%, mass fraction of substances insoluble in hydrochloric acid not more than 0.05%, mass fraction of iron not more than 0.005%, mass fraction of impurities of each of Ti, Co, Mo, V, Sb, Ba cations not more than 1 ppm, Pb, Cd, As, Hg not more than 0.1 ppm.

Method for the production of active high-purity magnesium oxide including the surface treated one consists of calcination of magnesium hydroxide obtained by interaction of magnesium salt solution with alkaline agent. Magnesium hydroxide crystals are produced by continuous method in divided and isolated between each other zones in the presence of seed crystals of magnesium hydroxide and liquid oil products with mole ratio of ions of alkaline agent and magnesium chloride OH.sup./Mg.sup.++ within the range (1.92.1):1, with the temperature in all zones not less than 40 C. and magnesium hydroxide crystals suspension residence time in each isolated zone not less than 20 minutes.

Active high-purity magnesium oxide produced by this method has high activity and high chemical purity that allows to use it as a filler for rubbers, adhesives, plastics, polymers, as stabilizers in production of chloroprene rubbers, refining additives of organic solvents, in production of catalysts, special ceramics, special glass, in pharmaceutical, pharmacopoeial and food industries, in production of magnesia cement and other magnesium-containing materials.

The invention is referred to chemical technology, namely to active high-purity magnesium oxide and its production method.

Active high-purity magnesium oxide, including the surface treated one, has BET specific surface area from 70 to 200 m.sup.2/g, average particle size (d50) determined by laser diffraction method not more than 10 microns, iodine activity in the range from 70 to 200 mg J/g MgO, citric activity not more than 40 s, pore volume in the range from 3.210.sup.2 cm.sup.3/g to 10.210.sup.2 cm.sup.3/g, diameter of 10% of the particles not more than 2 microns, diameter of 90% of the particles not more than 30 microns, mass fraction of residue on the 150 micron sieve not more than 1%, mass fraction of residue on the 45 micron sieve not more than 2%, mass fraction of chlorides not more than 0.1%, mass fraction of calcium not more than 0.1%, mass fraction of substances insoluble in hydrochloric acid not more than 0.05%, mass fraction of iron not more than 0.005%, mass fraction of impurities of each of Ti, Co, Mo, V, Sb, Ba cations not more than 1 ppm, Pb, Cd, As, Hg not more than 0.1 ppm.

Method for the production of active high-purity magnesium oxide including the surface treated one consists of calcination of magnesium hydroxide obtained by interaction of magnesium salt solution with alkaline agent. Magnesium hydroxide crystals are produced by continuous method in divided and isolated between each other zones in the presence of seed crystals of magnesium hydroxide and liquid oil products with mole ratio of ions of alkaline agent and magnesium chloride OH.sup./Mg.sup.++ within the range (1.92.1):1, with the temperature in all zones not less than 40 C. and magnesium hydroxide crystals suspension residence time in each isolated zone not less than 20 minutes.

Active high-purity magnesium oxide produced by this method has high activity and high chemical purity that allows to use it as a filler for rubbers, adhesives, plastics, polymers, as stabilizers in production of chloroprene rubbers, refining additives of organic solvents, in production of catalysts, special ceramics, special glass, in pharmaceutical, pharmacopoeial and food industries, in production of magnesia cement and other magnesium-containing materials.

The present application relates to an apparatus for producing magnesium oxide, a method for producing magnesium oxide by using same, magnesium oxide produced thereby, and use of the magnesium oxide. According to the apparatus for producing magnesium oxide, the method for producing magnesium oxide by using same and the magnesium oxide produced thereby of the present application, the magnesium oxide may have high thermal conductivity at low costs, a small spherical particle size, and a dense structure. Such magnesium oxide can be used as a heat-dissipating filler.

The present application relates to an apparatus for producing magnesium oxide, a method for producing magnesium oxide by using same, magnesium oxide produced thereby, and use of the magnesium oxide. According to the apparatus for producing magnesium oxide, the method for producing magnesium oxide by using same and the magnesium oxide produced thereby of the present application, the magnesium oxide may have high thermal conductivity at low costs, a small spherical particle size, and a dense structure. Such magnesium oxide can be used as a heat-dissipating filler.

An object of the present invention is to provide magnesium oxide particles that have a high heat conductivity and excellent properties as heat-dissipating filler, and can prevent problems such as soft errors in the memory. The magnesium oxide particles have a BET specific surface area of 0.1 to 17 m.sup.2/g, and an dose of 0.005 c/cm.sup.2.Math.Hr or lower, the particles exhibiting a relation between an X-ray diffraction peak intensity y (cps) at a Bragg angle (2) of 42.80 to 43.00 and the BET specific surface area x (m.sup.2/g) as represented by the following inequality (1):
y960x+33000(1).

An object of the present invention is to provide magnesium oxide particles that have a high heat conductivity and excellent properties as heat-dissipating filler, and can prevent problems such as soft errors in the memory. The magnesium oxide particles have a BET specific surface area of 0.1 to 17 m.sup.2/g, and an dose of 0.005 c/cm.sup.2.Math.Hr or lower, the particles exhibiting a relation between an X-ray diffraction peak intensity y (cps) at a Bragg angle (2) of 42.80 to 43.00 and the BET specific surface area x (m.sup.2/g) as represented by the following inequality (1):
y960x+33000(1).

Nanowires useful as heterogeneous catalysts are provided. The nanowire catalysts are useful in a variety of catalytic reactions, for example, the oxidative coupling of methane to C2 hydrocarbons. Related methods for use and manufacture of the same are also disclosed.

Nanowires useful as heterogeneous catalysts are provided. The nanowire catalysts are useful in a variety of catalytic reactions, for example, the oxidative coupling of methane to C2 hydrocarbons. Related methods for use and manufacture of the same are also disclosed.