A denitrification system for removing nitrates in a water body by electrocatalytic hydrogen evolution and catalytic hydrogenation is disclosed. The denitrification system includes an electrolytic cell and a three-electrode system inserted into the electrolytic cell. The electrolytic cell contains electrolyte solution, and the denitrification catalyst is dispersed and suspended in the electrolyte solution. The three-electrode system includes a working electrode, a counter electrode and a reference electrode. The counter electrode adopts Pt sheet, the working electrode adopts the catalyst Ni.sub.3S.sub.2—NF, and the preparation steps of the catalyst Ni.sub.3S.sub.2—NF are as follows: (i) cutting a certain size nickel mesh and cleaning it; (ii) adding the cleaned nickel mesh into thiourea solution; (iii) reacting under hydrothermal conditions, and washing and drying to obtain the catalyst Ni.sub.3S.sub.2—NF. The invention avoids the hazards of storing and transporting hydrogen storage and realizes the efficient removal of nitrate in water by electrocatalytic hydrogen evolution and catalytic hydrogenation.

A transition metal-based heterogeneous carbonylation reaction catalyst has an excellent catalytic activity and selectivity in the carbonylation reaction and is easily separated from a product, by crosslinking polymerizing a transition metal-based homogeneous catalyst unit through a Friedel-Craft reaction. The catalyst may be used in a method for preparing lactone. The transition metal-based heterogeneous carbonylation reaction catalyst allows to produce lactone or succinic anhydride with an epoxide compound while showing a high selectivity, and can be applied in industrial very usefully due to easy separation from the product and thus reusing thereof.

The present invention relates to a transition metal-based heterogeneous carbonylation reaction catalyst that has an excellent catalytic activity and selectivity in the carbonylation reaction and is easily separated from a product, by crosslinking polymerizing a transition metal-based homogeneous catalyst unit through a Friedel-Craft reaction; and a method for preparing lactone using the same. The transition metal-based heterogeneous carbonylation reaction catalyst allows to produce lactone or succinic anhydride with an epoxide compound while showing a high selectivity, and can be applied in industrial very usefully due to easy separation from the product and thus reusing thereof.

A process for the production of middle distillates by the catalytically promoted hydration of olefinic compounds having a carbon number ranging from 7 to 14 to convert the olefins to the corresponding mixed alcohols having a higher boiling point that is in the diesel range, the process being conducted in a continuous stirred tank reactor, e.g., an ebullated-bed reactor, utilizing catalysts that include soluble homogeneous acidic compounds and solid heterogeneous compounds such as resins, and amorphous or structured metal oxides containing elements selected from IUPAC Groups 4-10, 13 and 14, and having Lewis or Bronsted acid sites.

A method for preparing a supported carbon catalyst, the method includes at least the following steps: contacting a gas containing an organic silicon source with a silicon oxide-based material to obtain a precursor; contacting the precursor with a gas containing an organic carbon source to obtain the supported carbon catalyst. The temperature and energy consumption of the chemical vapor deposition of heteroatom-containing carbon material on silica-based materials can be greatly reduced in this method, and the cost of the catalyst can be effectively reduced.

A method for preparing a supported carbon catalyst, the method includes at least the following steps: contacting a gas containing an organic silicon source with a silicon oxide-based material to obtain a precursor; contacting the precursor with a gas containing an organic carbon source to obtain the supported carbon catalyst. The temperature and energy consumption of the chemical vapor deposition of heteroatom-containing carbon material on silica-based materials can be greatly reduced in this method, and the cost of the catalyst can be effectively reduced.

A catalyst composition including nickel foam and a plurality of carbon-doped nickel oxide nanorods disposed on the nickel foam.

A catalyst composition including nickel foam and a plurality of carbon-doped nickel oxide nanorods disposed on the nickel foam.

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.

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.