A method and a device for preparing a carbon nanotube and a prepared carbon nanotube. The method includes: adding iron pentcarbonyl and nickel tetracarbonyl into a multi-stage series fluidized bed and performing decomposition to obtain a catalyst, and discharging the carbon monoxide generated; adding a carbon source and injecting an inert gas into the series fluidized bed for reaction under heating at 600-800° C. for 40-90 min, the ratio of the mass of carbon in the carbon source to the mass of the catalyst being 5-7:3-5. Further provided are a device for preparing a carbon nanotube according to the above method and a carbon nanotube prepared by the above method.

Disclosed herein are compositions comprising zirconium and cerium having a surprisingly small particle sizes. The compositions disclosed herein contain zirconium, cerium, optionally yttrium, and optionally one or more rare earths other than cerium and yttrium The compositions exhibit a particle size characterized by a Dso value of about 20 μm to about 45 μm and a D.sub.99 value of about 55 μm to about 1 00 μm. Further disclosed are processes of producing these compositions using oxalic acid in the process. The compositions can be used as a catalyst and/or part of a catalytic system for automobile exhaust gas.

A catalyst has a modified silica support and comprises a modifier metal, zirconium and/or hafnium, and a catalytic metal on the modified support. The catalyst has at least a proportion, typically, at least 25%, of modifier metal present in moieties having a total of up to 2 modifier metal atoms. The moieties may be derived from a monomeric and/or dimeric cation source. A method of production:— provides a silica support with isolated silanol groups with optional treatment to provide isolated silanol groups (—SiOH) at a level of <2.5 groups per nm.sup.2; contacting the optionally treated silica support with a monomeric zirconium or hafnium modifier metal compound to effect adsorption onto the support; optionally calcining the modified support for a time and temperature sufficient to convert the monomeric zirconium or hafnium compound adsorbed on the surface to an oxide or hydroxide of zirconium or hafnium in preparation for catalyst impregnation.

Disclosed herein are catalyst compositions having improved mercury intrusion volume and surface areas and processes for making these compositions. The enhanced compositions disclosed herein contain zirconium, cerium, optionally yttrium, and optionally one or more rare earths other than cerium and yttrium. Further disclosed are processes of producing these compositions involving supercritical drying after addition of mesitylene. The compositions can be used as a catalyst and/or as part of a catalyst system in an automobile exhaust system.

The present invention relates to catalytically active material, comprising grains of non-graphitizing carbon with iron nanoparticles dispersed therein, wherein d.sub.p, the average diameter of iron nanoparticles in the non-graphitizing carbon grains, is in the range of 1 nm to 20 nm, D, the average distance between iron nanoparticles in the non-graphitizing carbon grains, is in the range of 2 nm to 150 nm, and ω, the combined total mass fraction of metal in the non-graphitizing carbon grains, is in the range of 30 wt % to 70 wt % of the total mass of the non-graphitizing carbon grains, and wherein d.sub.p, D and ω conform to the following relation: 4.5 d.sub.p/ω>D≥0.25 d.sub.p/ω. The present invention, further, relates to a process for the manufacture of material according to the invention, as well as its use as a catalyst.

The present disclosure generally relates to a denitration catalyst, and in particular to a method for preparing the denitration catalyst. The present disclosure also relates to a method for preparing a coated substrate comprising the denitration catalyst. The present invention also relates to use of the denitration catalyst and/or coated substrate at low temperatures and/or humid environments.

The invention discloses a nitrogen-doped mesoporous carbon-coated Titanium dioxide composite photocatalyst, a preparation method and use thereof. The preparation method comprises the steps of: dissolving an organic ligand and Ti(OC.sub.3H.sub.7).sub.4 in a mixture of methanol and DMF at a certain ratio, performing a hydrothermal reaction, centrifuging and drying to obtain a Titanium-based metal organic framework (Ti-MOF); pyrolyzing the obtained Ti-MOF under an inert atmosphere, and oxidizing the same for etching to obtain a nitrogen-doped mesoporous carbon-coated Titanium dioxide composite photocatalyst. The obtained composite photocatalyst not only facilitates the adsorption, enrichment and mass transfer of low concentration VOCs, but also efficiently degrades VOCs under sunlight. It has high degradation activity and stability when performing photocatalytic removal of VOCs in the presence of visible light, is simple in synthesis, low in preparation cost, and has strong potential for the use in environmental protection.

A method of making an M-N—C catalyst is disclosed. The method includes the steps of (a) contacting an N-doped carbon support with a basic solution that includes a metal salt, whereby the N-doped carbon support is metalated by the metal cation of the metal salt to form one or more chelated metal-nitrogen complexes (MN.sub.x species); and (b) subsequently contacting the metalated N-doped carbon support with an acid, whereby the one or more MN.sub.x species formed on the N-doped carbon support in step (a) remain intact while other species are removed. The resulting composition may be catalytically activated by heat treating the composition. The activated catalyst may be used to catalyze a wide range of chemical reactions.

The present disclosure relates to a method for producing a metal carbide, where the method includes thermally treating a molecular precursor in an oxygen-free environment, such that the treating produces the metal carbide and the molecular precursor includes ##STR00001##
where M is the metal of the metal carbide, N* includes nitrogen or a nitrogen-containing functional group, and x is between zero and six, inclusively.

Processes for forming multimetallic catalysts by grafting nickel precursors to metal oxide supports. Dry reforming reaction catalysts having nickel and promotors grafted to metal oxides supports. Methanation reaction catalysts having nickel and promotors grafted to metal oxides supports.