A method for preparing methyl methacrylate from methacrolein and methanol. The process comprises contacting in a reactor a mixture comprising methacrolein, methanol and oxygen with a heterogeneous catalyst comprising a support and a noble metal, wherein said catalyst has an average diameter of at least 200 microns, liquid and gaseous reactants flow downward in the reactor and wherein the continuous phase in the reactor is a gas which has no more than 7.5 mol % oxygen at reactor inlets.

Disclosed are a catalyst for carbonylation of dimethyl ether that has high catalyst activity and can be regenerated using a fluidized bed reactor, and a method for preparing the same. The catalyst for carbonylation of dimethyl ether includes a support having a first density; and ferrierite zeolite catalyst particles bound to a surface of the support via a polymer binder and having a second density smaller than the first density.

A method for preparing a heterogeneous catalyst. The method comprises steps of: (a) combining (i) a support, (ii) an aqueous solution of a noble metal compound and (iii) a C.sub.2-C.sub.18 thiol comprising at least one hydroxyl or carboxylic acid substituent; to form a wet particle and (b) removing water from the wet particle by drying followed by calcination to produce the catalyst.

Provided are (i) a catalyst that has a core-shell structure and is highly active in an oxygen reduction reaction, which is a cathode reaction of a fuel cell, and (ii) a reaction acceleration method in which the catalyst is used. A core-shell catalyst for accelerating an oxygen reduction reaction, contains: silver or palladium as a core material; and platinum as a shell material, the core-shell catalyst having, on a surface thereof, a (110) surface of a face centered cubic lattice.

Provided is a catalyst for manufacturing multi-wall carbon nanotubes, the catalyst including metal components according to <Equation> Ma:Mb=x:y, and having a hollow structure with a thickness of 0.5-10 μm. In the above equation, Ma represents at least two metals selected from Fe, Ni, Co, Mn, Cr, Mo, V, W, Sn, and Cu; Mb represents at least one metal selected from Mg, Al, Si, and Zr; x and y each represent the molar ratio of Ma and Mb; and x+y=10, 2.0≤x≤7.5, and 2.5≤y≤8.0.

A core-shell structure supported catalyst and a preparation method and use thereof are disclosed. The core-shell structure supported catalyst includes a core-shell structure carrier and platinum supported on the surface of the core-shell structure carrier, wherein the core-shell structure carrier includes a ferroferric oxide nanoparticle core and a nitrogen-doped carbon shell, and a molar ratio of the ferroferric oxide nanoparticle core to platinum is 1:(0.03-0.3).

Disclosed is a ruthenium-based catalyst for ammonia synthesis, preparation method and use thereof. The ruthenium-based catalyst comprises Ru—Ba-A core-shell structure which comprises a ruthenium nanoparticle as a core covered with a first shell and a second shell sequentially, wherein the first shell consists of a barium nanoparticle, and the second shell consists of a metal oxide. The Ru—Ba-A core-shell structure can effectively preventing agglomerations of ruthenium nanoparticles during the use of the catalyst and avoiding direct contact between the ruthenium nanoparticles and the metal oxides. In addition, barium nanoparticles have a promoting effect as an electronic promoter, which can effectively improve the stability and catalytic activity of ruthenium-based catalyst for ammonia synthesis, especially in the system for synthesizing ammonia from a coal gas.

A catalyst that includes heterogeneous metal carbide nanomaterials and a novel preparation method to synthesize the metal carbide nanomaterials under relatively mild conditions to form an encapsulated transition metal and/or transition metal carbide nanoclusters in a support and/or binder. The catalyst may include confined platinum carbide nanoclusters. The preparation may include the treatment of encapsulated platinum nanoclusters with ethane at elevated temperatures. The catalysts may be used for catalytic hydrocarbon conversions, which include but are not limited to, ethane aromatization, and for selective hydrogenation, with negligible green oil production.

A process produces methyl methacrylate by direct oxidative esterification of methacrolein. Methyl methacrylate is used in large amounts for producing polymers and copolymers with other polymerizable compounds. An optimized workup of the reactor discharge from the oxidative esterification of methacrolein allows for co-discharged fine catalyst particles to be very efficiently separated and optionally removed or recycled. In addition, this process can reduce the formation of byproducts in extended continuous operation compared to known variant. A reactor system contains stirrer configurations which allow virtually abrasion-free operation and thus a catalyst on-stream time of several years.

A Ni—Al.sub.2O.sub.3@Al.sub.2O.sub.3—SiO.sub.2 catalyst with coated structure is provided. The catalyst has a specific surface area of 98 m.sup.2/g to 245 m.sup.2/g, and a pore volume of 0.25 cm.sup.3/g to 1.1 cm.sup.3/g. A mass ratio of an Al.sub.2O.sub.3 carrier to active component Ni in the catalyst is Al.sub.2O.sub.3:Ni=100:4˜26, a mass ratio of the Al.sub.2O.sub.3 carrier to an Al.sub.2O.sub.3—SiO.sub.2 coating layer is Al.sub.2O.sub.3:Al.sub.2O.sub.3—SiO.sub.2=100:0.1˜3, and a molar ratio of Al to Si in the Al.sub.2O.sub.3—SiO.sub.2 coating layer is 0.01 to 1. Ni particles are distributed on a surface of the Al.sub.2O.sub.3 carrier in an amorphous or highly dispersed state and have a grain size less than or equal to 8 nm, and the coating layer is filled among the Ni particles.