7 results about "Keggin structure" patented technology

The application discloses a preparation method of a mesoporous silicon-based composite material with phosphotungstic acid and titanium oxide simultaneously supported, and belongs to the technical field of catalytic material preparation. The method aims to solve the problems of easy aggregation of active components, easy damage of channel order and complex preparation process in the prior art. The method is characterized by the following steps: through a one-step hydrothermal synthesis strategy, a triblock copolymer is used as a structure directing agent, an alcohol solution of a titanium source precursor, a silicon source precursor and a Keggin type phosphotungstic acid is simultaneously added in an acid system, and then the mesoporous silicon-based composite material is prepared through hydrothermal crystallization, washing, drying and calcination. The method is simple in process and controllable in operation, and the obtained material has the following advantages: two-dimensional hexagonal ordered mesoporous structure, large specific surface area, high dispersion of titanium and phosphotungstic acid, intact Keggin structure, good double-acid-site synergistic catalytic effect, and suitability for acid catalytic reactions, especially in the field of biomass conversion.

The application discloses a silane-bonded aluminum-silicon-based supermolecular defluorination coagulant as well as a preparation method and application thereof, and belongs to the technical field of water treatment. The silane-bonded aluminum-silicon-based supermolecular defluorination coagulant is constructed by silane coupling to form a ≡Si-(CH2)3-NH2 supermolecular capture site, so that the hydrogen bond adsorption of fluorine ions is enhanced. The Si-O-Al grid structure is accurately controlled by a pulse gradient assembly strategy, so that efficient complexation of fluorine ions is realized. Fractional pressure immersion ensures that the Keggin structure aluminum active component is embedded, and the removal rate of low-fluorine water is significantly improved. The silane-bonded aluminum-silicon-based supermolecular defluorination coagulant can efficiently remove fluorine ions in low-concentration fluorine-containing wastewater, and is especially suitable for wastewater treatment in the photovoltaic industry.

The application discloses an oxidative desulfurization catalyst, which is a litchi shell activated carbon loaded with phosphomolybdic acid; the litchi shell activated carbon is prepared by activating litchi shell carbon. The phosphomolybdic acid is loaded on the litchi shell activated carbon carrier, which not only combines with the oxygen-containing functional groups on the surface of the litchi shell activated carbon, but also disperses the HPMo on the surface of the litchi shell activated carbon carrier, so that more HPMo acid centers are provided for the oxidation reaction, and the catalytic oxidative desulfurization activity is good. The oxidative desulfurization catalyst is prepared by the impregnation method, the phosphomolybdic acid is easy to be loaded on the surface of the litchi shell activated carbon, and the Keggin structure of the phosphomolybdic acid is not destroyed, that is, the HPMo molecules with the complete Keggin structure exist on the catalyst, the Mo(VI) sites of the HPMo molecules can interact with the oxidant hydrogen peroxide to produce active free radical species, so that the desulfurization efficiency is effectively improved.

The invention provides a method for preparing levulinic acid at low temperature, according to the method, in a closed reactor, pentahydroxymethyl furfural is subjected to a photo-thermal catalytic reaction in water to obtain levulinic acid, a catalyst of the photo-thermal catalytic reaction is a polyoxometallate catalyst with a cobalt-based Keggin structure, the selectivity of the levulinic acid is remarkably improved, and the selectivity of the levulinic acid is improved. And comprehensive energy consumption and environmental burden are reduced.

The present application relates to the technical field of biodiesel preparation, and particularly discloses a metal-doped vacancy-type polyoxometalate ionic liquid, a preparation method and application thereof. The ionic liquid is composed of sulfonic acid group (-SO3H) containing organic cations derived from 1,3-propane sultone and vacancy-type Keggin structure heteropolyanions (PW 2+ MO 40 ) doped with metals (Zn 3+ , Fe 4+ or Sn 11 ), forming a bifunctional synergistic catalytic system with stable Brønsted acid sites and controllable Lewis acid sites. The catalyst can simultaneously and efficiently catalyze esterification and transesterification, realize the "one-pot" conversion of high-acid-value oil and fat raw materials, significantly improve the biodiesel yield, and due to the unique structure, the active sites are stable and not easy to be lost, and the recycling performance is excellent. The present application provides a new multifunctional catalyst for green and efficient production of biodiesel, and has important industrial application prospect.

The application relates to the technical field of organic synthesis, in particular to a method for electrocatalytically synthesizing N-tert-butyl-2-benzothiazolesulfenamide. The method comprises the following steps: dispersing raw material 2-mercaptobenzothiazole, a catalyst, an electrolyte and tert-butylamine in a solvent, uniformly mixing the raw material, the catalyst, the electrolyte and the tert-butylamine, and obtaining a reaction solution; placing the reaction solution in an electrolytic cell, and electrocatalytically oxidizing to obtain N-tert-butyl-2-benzothiazolesulfenamide; wherein the catalyst is a Keggin structure quaternary ammonium salt of phosphotungstic acid or a Keggin structure quaternary ammonium salt of silicotungstic acid. Inorganic ammonium salt is used as the electrolyte, and the Keggin structure quaternary ammonium salt of phosphotungstic acid or the Keggin structure quaternary ammonium salt of silicotungstic acid is used as an electrocatalytic promoter, so that a stable and continuously-operable electrocatalytic synthesis system under low current conditions is constructed, and the reaction rate and the yield of the target product N-tert-butyl-2-benzothiazolesulfenamide are significantly improved.