A method for preparing methyl methacrylate from methacrolein and methanol; said method comprising contacting in a reactor a mixture comprising methacrolein, methanol and oxygen with a catalyst bed of heterogeneous catalyst comprising a support and a noble metal, wherein mass transfer rate of oxygen in hour.sup.1 divided by space-time yield in moles methyl methacrylate/kg.Math.catalyst hour in the catalyst bed is at least 20.

A method for preparing methyl methacrylate from methacrolein and methanol; said method comprising contacting in a reactor a mixture comprising methacrolein, methanol and oxygen with a heterogeneous catalyst comprising a support and a noble metal, wherein pH at the reactor outlet is from 3 to 6.7.

A process for the synthesis of linear paraffinic hydrocarbons from a feed of carbon monoxide and dihydrogen in the presence of a catalyst of a mesoporous oxide matrix and a content by weight of the element cobalt of 0.5% to 60%, wherein the catalyst is prepared by a) mixing, in an aqueous or hydro-organic solvent, a molecular precursor containing cobalt and a molecular precursor of the mesoporous oxide matrix containing element X of silicon, aluminium, titanium, zirconium and or cerium; b) aerosol spray drying the mixture to form spherical liquid droplets; c) drying to obtain solid particles at a temperature of 10 C. to 300 C.; d) activation by a reduction treatment to form nanoparticles of cobalt with an oxidation state of 0.

A packing member for use in a packed bed. The packing member includes ceramic material and surface structures on the outer surface of the packing member. The packing member does not include a fluid communication intra-particle channel extending through the packing member from a first aperture on a first side of the packing member to a second aperture on a substantially opposing second side of the packing member. Also described is a supported catalyst, apparatus and a method of production.

A method of preparing hollow molybdate composite microspheres includes steps of: (1) dissolving 1-4 mmol of MCl.sub.2 in 20 ml of water to obtain a solution A and dissolving 1-4 mmol. of molybdic acid in 20 ml of water to obtain a solution B, followed by mixing the solution A and the solution B, in which M is Co, Ni, or Cu; (2) dissolving 10-40 mmol of urea in 40 ml of water, adding the mixed solution of step (1) and stirring uniformly; (3) placing the mixed solution of step (2) into a reaction vessel and reacting at 120-160 C. for 6-12 hours; (4) suction filtrating and water washing, followed by drying in a vacuum oven at 40-60 C.; (5) calcination at 350-500 C. for 2-4 hours in a Muffle furnace.

The present invention belongs to the technical field of photocatalytic materials and preparation thereof, and more particularly, relates to a double-layer ZnO hollow sphere photocatalytic material. The double-layer ZnO hollow sphere photocatalytic material is formed by inner and outer layers of ZnO hollow spheres; the hollow spheres on the inner layer have a diameter of 1.0-2.5 m; and the hollow spheres on the outer layer have a diameter of 1.5-4.5 m. The present invention further relates to a preparation method of the double-layer ZnO hollow sphere photocatalytic material, which comprises the following steps of: dissolving dissolvable zinc salt into a mixture of monohydric alcohol and ethylene glycol to prepare a solution, and then performing a solvothermal reaction on the solution under airtight conditions to prepare the double-layer ZnO hollow sphere photocatalytic material.

A catalyst for a selective conversion of hydrocarbons. The catalyst includes a first component selected from the group consisting of Group VIII noble metals and mixtures thereof, a second component selected from the group consisting of alkali metals or alkaline-earth metals and mixtures thereof, and a third component selected from the group consisting of tin, germanium, lead, indium, gallium, thallium and mixtures thereof. The catalyst is a support formed as a spherical catalyst particle with a median diameter between 1.6 mm and 2.5 mm and an apparent bulk density between 0.6 and 0.3 g/cc. Also a process of using such a catalyst for a selective hydrocarbon conversion reaction and a process for regenerating such a catalyst by removing coke from same.

Processes for dehydrogenation of a hydrocarbon feedstock are described. The process can be run at lower H.sub.2/HC ratios and lower RITs while maintaining coke production at the same level as operation at higher H.sub.2/HC ratios and higher RITs without decreasing the yield per pass. Acceptable levels of coke were achieved when operating the process at low hydrogen to hydrocarbon molar ratio in the range of 0.01 to 0.40 and reactor inlet temperatures in the range of 500-645 C. The process uses a low coke catalyst.

Large pill dehydrogenation catalysts and large screens slot width are combined in dehydrogenation units to reduce the pressure drop across the catalyst bed and reactor screens compared to conventional screen and catalyst size combinations. The catalyst has an average pill diameter in the range of 1.6 mm to 3.0 mm, and the slot width of the screen is in the range of about 30% to about 60% of the pill diameter.

The invention discloses a method for catalytically hydrogenating oxalates. In the method, an oxalate and hydrogen gas are contacted with a nanotube assembled hollow sphere catalyst, to produce a product comprising glycolate or glycol. The predominant chemical components of the catalyst include copper and silica, in which the copper is in an amount of 5 to 60% by weight of the catalyst, and the silica is in an amount of 40-95% by weight of the catalyst. The catalyst has a specific surface area of 450-500 m.sup.2/g, an average pore volume of 0.5-1 cm.sup.3/g, and an average pore diameter of 5-6 nm. The catalyst is in a structure of assembling nanotubes on hollow spheres, wherein the hollow spheres have a diameter of 50-450 nm, and a wall thickness of 10-20 nm, and the nanotubes, vertically arranged on the surfaces of the hollow spheres, have a diameter of 3-5 nm, and a length of 40-300 nm. Even in the case of a low H.sub.2/DMO feeding ratio, the method of the invention still can exhibit an excellent activity of hydrogenating oxalates and an excellent selectivity to ethylene glycol, and reduce circulation quantity of hydrogen gas, thereby to save power costs and apparatus costs, and it can flexibility adjust the selectivity of ethylene glycol and glycolate. Thus, the method has high industry prospects and application values.