A method of synthesizing a doped carbonaceous material includes mixing a carbon precursor material with at least one dopant to form a homogeneous/heterogeneous mixture; and subjecting the mixture to pyrolysis in an inert atmosphere to obtain the doped carbonaceous material. A method of purifying water includes providing an amount of the doped carbonaceous material in the water as a photocatalyst; and illuminating the water containing the doped carbonaceous material with visible light such that under visible light illumination, the doped carbonaceous material generates excitons (electron-hole pairs) and has high electron affinity, which react with oxygen and water adsorbed on its surface forming reactive oxygen species (ROS), such as hydroxyl radicals and superoxide radicals, singlet oxygen, hydrogen peroxide, that, in turn, decompose pollutants and micropollutants.

It is an object to provide a regenerated denitration catalyst whose denitration performance is restored compared with a denitration catalyst before use, utilizing a spent denitration catalyst, and a method for manufacturing the same. In a regenerated denitration catalyst according to the present disclosure, a spent denitration catalyst including a first titanium oxide as a main component, and a second titanium oxide are mixed. The spent denitration catalyst is already used in a denitration reaction in which nitrogen oxides in a gas are decomposed into nitrogen and water using a reducing agent. The second titanium oxide has a larger specific surface area per unit weight than the first titanium oxide. A content of the second titanium oxide based on a total weight of the first titanium oxide and the second titanium oxide is preferably 10% by weight or more and 90% by weight or less.

It is an object to provide a regenerated denitration catalyst whose denitration performance is restored compared with a denitration catalyst before use, utilizing a spent denitration catalyst, and a method for manufacturing the same. In a regenerated denitration catalyst according to the present disclosure, a spent denitration catalyst including a first titanium oxide as a main component, and a second titanium oxide are mixed. The spent denitration catalyst is already used in a denitration reaction in which nitrogen oxides in a gas are decomposed into nitrogen and water using a reducing agent. The second titanium oxide has a larger specific surface area per unit weight than the first titanium oxide. A content of the second titanium oxide based on a total weight of the first titanium oxide and the second titanium oxide is preferably 10% by weight or more and 90% by weight or less.

A method for preparing an active catalyst for high-efficiency denitration is disclosed. The method includes: a catalyst raw material is charged into a denitration reactor, NH.sub.3 and an inert gas are introduced and then heating is performed, and the temperature is held and then natural cooling is performed, thereby obtaining the catalyst. The active catalyst can greatly improve the denitration activity in low temperature range, and can not only improve the denitration efficiency under the condition without SO.sub.2 and H.sub.2O, but also can improve the denitration efficiency under the condition with both SO.sub.2 and H.sub.2O. The service life of the catalyst is prolonged under the premise of not changing the existing catalyst preparation process, and the economic benefit is significant. The denitration efficiency of a powder catalyst can be increased by 25%, and the denitration efficiency of a honeycombed catalyst or a corrugated catalyst can be increased by 20%.

This invention relates to azirconium hydroxideor zirconium oxide comprising, on an oxide basis, up to 30 wt % of a dopant comprising one or more of silicon, sulphate, phosphate, tungsten, niobium, aluminium, molybdenum, titanium or tin, and having acid sites, wherein the majority of the acid sites are Lewis acid sites. In addition, the invention relates to a catalyst, catalyst support or precursor, binder, functional binder, coating or sorbent comprising the zirconium hydroxide or zirconium oxide. The invention also relates to a process for preparing zirconium hydroxide, the process comprising the steps of:(a) dissolving a zirconium salt in an aqueous acid, (b) addingone or more complexing agents to the resulting solution or sol, the one or more complexing agents being an organic compound comprising at least one of the following functional groups: an amine, an organosulphate, a sulphonate, a hydroxyl, an ether or a carboxylic acid group, (c) heating the solution or sol formed in step (b), (d) adding a sulphating agent, and (e) adding a base to form a zirconium hydroxide, and (f) optionally adding a dopant.

This invention relates to azirconium hydroxideor zirconium oxide comprising, on an oxide basis, up to 30 wt % of a dopant comprising one or more of silicon, sulphate, phosphate, tungsten, niobium, aluminium, molybdenum, titanium or tin, and having acid sites, wherein the majority of the acid sites are Lewis acid sites. In addition, the invention relates to a catalyst, catalyst support or precursor, binder, functional binder, coating or sorbent comprising the zirconium hydroxide or zirconium oxide. The invention also relates to a process for preparing zirconium hydroxide, the process comprising the steps of:(a) dissolving a zirconium salt in an aqueous acid, (b) addingone or more complexing agents to the resulting solution or sol, the one or more complexing agents being an organic compound comprising at least one of the following functional groups: an amine, an organosulphate, a sulphonate, a hydroxyl, an ether or a carboxylic acid group, (c) heating the solution or sol formed in step (b), (d) adding a sulphating agent, and (e) adding a base to form a zirconium hydroxide, and (f) optionally adding a dopant.

A catalyst composition comprising (a) carrier comprising (i) 5 to 95 wt % mordenite type zeolite having a mean crystallite length parallel to the direction of the 12-ring channels of 60 nm or less and a mesopore volume of at least 0.10 cc/gram, (ii) 5 to 95 wt % ZSM-5 type zeolite; and (iii) 10 to 60 wt % inorganic binder; and (b) 0.001 to 10 wt % of one or more catalytically active metals, wherein the inorganic binder comprises titania, its preparation and its use in alkylaromatic conversion.

A catalyst composition comprising (a) carrier comprising (i) 5 to 95 wt % mordenite type zeolite having a mean crystallite length parallel to the direction of the 12-ring channels of 60 nm or less and a mesopore volume of at least 0.10 cc/gram, (ii) 5 to 95 wt % ZSM-5 type zeolite; and (iii) 10 to 60 wt % inorganic binder; and (b) 0.001 to 10 wt % of one or more catalytically active metals, wherein the inorganic binder comprises titania, its preparation and its use in alkylaromatic conversion.

A catalyst system, which is active in pyrolyzing methane at reaction temperatures above 700° C., comprising a molten salt selected from the group consisting of the halides of alkali metals; the halides of alkaline earth metals; the halides of zinc, copper, manganese, cadmium, tin and iron; and mixtures thereof, the molten salt having dispersed therein one or more catalytically active forms of iron, molybdenum, manganese, nickel, cobalt, zinc, titanium, and copper in the form of finely divided elemental metals, metal oxides, metal carbides or mixtures thereof.

A catalyst system, which is active in pyrolyzing methane at reaction temperatures above 700° C., comprising a molten salt selected from the group consisting of the halides of alkali metals; the halides of alkaline earth metals; the halides of zinc, copper, manganese, cadmium, tin and iron; and mixtures thereof, the molten salt having dispersed therein one or more catalytically active forms of iron, molybdenum, manganese, nickel, cobalt, zinc, titanium, and copper in the form of finely divided elemental metals, metal oxides, metal carbides or mixtures thereof.