A method of forming a carbon nanotube array substrate is disclosed. One embodiment comprises depositing a composite catalyst layer on the substrate, oxidizing the composite catalyst layer, reducing the oxidized composite catalyst layer, and growing the array on the composite catalyst layer. The composite catalyst layer may comprise a group VIII element and a non-catalytic element deposited onto the substrate from an alloy. In another embodiment, the composite catalyst layer comprises alternating layers of iron and a lanthanide, preferably gadolinium or lanthanum. The composite catalyst layer may be reused to grow multiple carbon nanotube arrays without additional processing of the substrate. The method may comprise bulk synthesis by forming carbon nanotubes on a plurality of particulate substrates having a composite catalyst layer comprising the group VIII element and the non-catalytic element. In another embodiment, the composite catalyst layer is deposited on both sides of the substrate.

A method of forming a carbon nanotube array substrate is disclosed. One embodiment comprises depositing a composite catalyst layer on the substrate, oxidizing the composite catalyst layer, reducing the oxidized composite catalyst layer, and growing the array on the composite catalyst layer. The composite catalyst layer may comprise a group VIII element and a non-catalytic element deposited onto the substrate from an alloy. In another embodiment, the composite catalyst layer comprises alternating layers of iron and a lanthanide, preferably gadolinium or lanthanum. The composite catalyst layer may be reused to grow multiple carbon nanotube arrays without additional processing of the substrate. The method may comprise bulk synthesis by forming carbon nanotubes on a plurality of particulate substrates having a composite catalyst layer comprising the group VIII element and the non-catalytic element. In another embodiment, the composite catalyst layer is deposited on both sides of the substrate.

Disclosed in the present invention is a chromium-free catalyst for gas-phase fluorination and an application thereof. The precursor of the related chromium-free catalyst for gas-phase fluorination consists of a compound containing iron element, a compound containing rare earth metal element and a compound containing element A, wherein element A is one selected from Ca, Al, Mg and Ti, the precursor is subjected to calcination and fluorination treatment to obtain the chromium-free catalyst for gas-phase fluorination. The precursor of the catalyst is calcined at 400-500° C. and fluorinated with hydrogen fluoride at 350-450° C. to obtain the chromium-free fluorinated catalyst. The catalyst has characteristics of being chromium-free and environment-friendly, good catalytic activity and long life etc. The catalyst can be used for preparing hydrofluoroolefins or hydrochlorofluoroolefins from halohydrocarbons.

Disclosed in the present invention is a chromium-free catalyst for gas-phase fluorination and an application thereof. The precursor of the related chromium-free catalyst for gas-phase fluorination consists of a compound containing iron element, a compound containing rare earth metal element and a compound containing element A, wherein element A is one selected from Ca, Al, Mg and Ti, the precursor is subjected to calcination and fluorination treatment to obtain the chromium-free catalyst for gas-phase fluorination. The precursor of the catalyst is calcined at 400-500° C. and fluorinated with hydrogen fluoride at 350-450° C. to obtain the chromium-free fluorinated catalyst. The catalyst has characteristics of being chromium-free and environment-friendly, good catalytic activity and long life etc. The catalyst can be used for preparing hydrofluoroolefins or hydrochlorofluoroolefins from halohydrocarbons.

The invention relates to a process for preparing aluminates of the general formula (I)

A.sub.1B.sub.xAl.sub.12-xO.sub.19-y where A is at least one element from the group consisting of Sr, Ba and La, B is at least one element from the group consisting of Mn, Fe, Co, Ni, Rh, Cu and Zn, x=0.05-1.0, y is a value determined by the oxidation states of the other elements, which comprises the steps (i) provision of one or more solutions or suspensions comprising precursor compounds of the elements A and B and also a precursor compound of aluminum in a solvent, (ii) conversion of the solutions or suspensions or the solutions into an aerosol, (iii) introduction of the aerosol into a directly or indirectly heated pyrolysis zone, (iv) carrying out of the pyrolysis and (v) separation of the resulting particles comprising hexaaluminate of the general formula (I) from the pyrolysis gas.

The invention relates to a process for preparing aluminates of the general formula (I)

A.sub.1B.sub.xAl.sub.12-xO.sub.19-y where A is at least one element from the group consisting of Sr, Ba and La, B is at least one element from the group consisting of Mn, Fe, Co, Ni, Rh, Cu and Zn, x=0.05-1.0, y is a value determined by the oxidation states of the other elements, which comprises the steps (i) provision of one or more solutions or suspensions comprising precursor compounds of the elements A and B and also a precursor compound of aluminum in a solvent, (ii) conversion of the solutions or suspensions or the solutions into an aerosol, (iii) introduction of the aerosol into a directly or indirectly heated pyrolysis zone, (iv) carrying out of the pyrolysis and (v) separation of the resulting particles comprising hexaaluminate of the general formula (I) from the pyrolysis gas.

A process for producing propylene glycol from glycerol including a catalyst of Cu and Ce at concentrations of up to 15% of each metal. In addition, it is described a catalyst of Cu and Ce to perform the selective reduction of glycerol and the process of production of such catalyst.

A process for producing propylene glycol from glycerol including a catalyst of Cu and Ce at concentrations of up to 15% of each metal. In addition, it is described a catalyst of Cu and Ce to perform the selective reduction of glycerol and the process of production of such catalyst.

A process has been developed for preparing a Fischer-Tropsch catalyst precursor and a Fischer-Tropsch catalyst made from the precursor. The process includes preparing a catalyst precursor by contacting a boehmite material with a stabilizer containing vanadium-phosphorus. The boehmite material includes two or more different crystalline boehmites having the same average crystallite size to the nearest whole nanometer and having differing properties selected from surface area, pore volume, density and combinations thereof. The boehmite material is subjected to at least one heat treatment at a temperature of at least 500° C., either before or after the contacting step to obtain a stabilized catalyst support having a pore volume of at least 0.3 cc/g. A catalytic metal or a compound containing cobalt is applied to the stabilized catalyst support to form the catalyst precursor. Finally, the catalyst precursor is reduced to activate the catalyst precursor to obtain the Fischer Tropsch catalyst. The catalyst has enhanced hydrothermal stability as measured by losing no more than 6% of its pore volume when exposed to water vapor.

A method for producing a catalyst or catalyst precursor is described including: applying a slurry of a particulate catalyst compound in a carrier fluid to an additive layer manufactured support structure to form a slurry-impregnated support, and drying and optionally calcining the slurry-impregnated support to form a catalyst or catalyst precursor. The mean particle size (D50) of the particulate catalyst compound in the slurry is in the range 1-50 μm and the support structure has a porosity ≧0.02 ml/g.