7 results about "Ammonium heptamolybdate" patented technology

This invention discloses a method for preparing a catalyst for the oxidative dehydrogenation of ethane, comprising the following steps: dissolving ammonium heptamolybdate tetrahydrate, ammonium metavanadate, telluric acid, and a dispersant in deionized water to form a mixed solution; adding an aqueous solution of niobium oxalate to the mixed solution within 15–50 min to form a suspension; then adding an aqueous solution of the template agent polyether P123; and subjecting the process to aging, hydrothermal crystallization, drying, calcination, and removal of the M2 phase to obtain the catalyst for the oxidative dehydrogenation of ethane. This invention introduces a dispersant and the template agent polyether P123 at specific steps in the catalyst preparation process, combined with limiting the time of adding the niobium oxalate aqueous solution to the mixed solution, which effectively improves the pore structure and specific surface area of ​​the catalyst, increases the proportion of high-concentration active sites on its terminal surface, and thus significantly enhances the catalyst's reactivity.

The application discloses a kind of high-strength flat plate catalyst and preparation method thereof, it is related to catalyst technical field.The technical scheme is as follows: including the following mass fraction components: titanium dioxide 50-80 parts, high-viscosity kaolin 2-15 parts, glass fiber 2-10 parts, carbon fiber 2-10 parts, plasticizer 2-15 parts, ammonium heptamolybdate 0.5-2 parts, ammonium metavanadate 0.5-2 parts and water 10-30 parts.The high-viscosity kaolin is prepared, and then combined with the subsequent high-temperature coating process, the adhesion between the catalyst mud and the stainless steel screen plate is greatly improved, thereby enhancing the stability of the catalyst, prolonging the service life of the catalyst and improving the catalytic reaction efficiency.

The patent discloses a preparation method of Mo-V-Sb-Na-O composite oxide catalyst and application of the Mo-V-Sb-Na-O composite oxide catalyst in a reaction of preparing acrylic acid from propylene aldehyde, and comprises the following steps: using a solvent evaporation method to prepare a Mo-V series catalyst, dissolving ammonium heptamolybdate, ammonium metavanadate and antimony trioxide in deionized water and uniformly mixing under rapid stirring, and drying and calcining the mixed liquid to obtain a high-activity catalyst for selectively oxidizing propylene aldehyde into acrylic acid, i.e. a composite oxide catalyst. The composite oxide catalyst prepared by the above method has the advantages of simple operation process, short preparation time, good selectivity and yield of acrylic acid.

The current invention describes the synthesis of heterogeneous composite comprising laponite and heptamolybdate by wetness impregnation method. Different experimental settings were used to carry out the synthesis, including the heptamolybdate ammonium dose (1.5, 1 or 0.5 g), ion exchanger dose tetrabutyl ammonium bromide (0.5, 0.25 or 0.125g), reaction duration (12 or 24h) and calcination temperature (200, 300 and 400 °C) for 2 hours. The optimal synthesis composition of the laponite / molybdate (Lap-Mo) is as follows: 5 g of Lap + 0.5 g of TBA + 1.5 g of heptamolybdate ammonium with reaction duration of 24 h and a calcination temperature of 300 °C for 2 hours under air. The laponite / molybdate composite have been used in an AOP to degrade MB dye in presence of H2O2 as an oxidant under visible light radiation. The AOP experiment have been optimized using RSM based on BBD. Under the optimum conditions: contact time=72 min, [H2O2 / Lap-Mo] wt% ratio= 1.24, dye concentration= 20.95 mg.L-1 pH= 8.3 reaching a 99% of degradation rate. The Lap-Mo catalyst degradation efficiency was also tested for other dyes such as safranin T (ST) and rhodamine B (RhB) as cationic dyes and methyl orange (MO) as anionic dye. Indeed, they exhibits a highly degradation rate equal to 96, 90 and 89% for ST, RhB and MO, respectively. Advantageously, the invention intends to promote, profitably, and efficiently dye degradation using the laponite / molybdate composite. Furthermore, the potential of the invention falls within the framework of improving wastewater treatment and paves the way to more areas of application in multiple industries.

The application provides a low-temperature sulfur-resistant denitration catalyst and a preparation method thereof, and the preparation method comprises the following steps: adding titanium dioxide into deionized water under stirring to obtain a base slurry; dissolving ammonium metavanadate in dilute sulfuric acid to react to generate vanadyl sulfate, adjusting the pH value to 2-4, and then standing and aging to obtain a vanadium precursor solution; dissolving ammonium heptamolybdate in deionized water, adding dilute sulfuric acid to adjust the pH value to 2-4, and then obtaining a molybdenum precursor solution; first adding the molybdenum precursor solution into the base slurry, mixing uniformly, then adding the vanadium precursor solution, continuing to stir, then adding an additive, stirring uniformly, and controlling the pH value of the slurry in the mixing process to be in the range of 2-4 to obtain a mixed slurry; and performing spray drying and calcination on the mixed slurry, and obtaining the low-temperature sulfur-resistant denitration catalyst after cooling. The catalyst prepared in the application has the characteristics of high dispersion of active components, high low-temperature denitration efficiency, excellent sulfur resistance and the like under the conditions of low temperature and high-sulfur flue gas.

The application discloses a Mo-Ru double-site transition metal catalyst and a preparation method thereof, and belongs to the technical field of electrocatalytic materials. The method uses graphene oxide as a carrier, adds a mixed solution of ruthenium trichloride trihydrate and ammonium heptamolybdate tetrahydrate into a graphene oxide dispersion solution, and performs ultrasonic treatment for 6 hours to obtain a uniform precursor solution; then, a hydrothermal reaction is performed to obtain a solid product; after the product is freeze-dried for 12 hours, a chemical vapor deposition method is used to perform high-temperature nitridation on the product at 800 DEG C under an ammonia-argon mixed atmosphere for 2 hours, and finally, the Mo-Ru double-site transition metal catalyst is prepared. The catalyst exhibits excellent two-electron hydrogen evolution reaction electrocatalytic activity and long-term stability in acidic and alkaline media, and can be efficiently applied to the field of hydrogen production by water electrolysis.

The present invention relates to the technical field of catalysts. Disclosed are a high-strength flat-plate catalyst and a preparation method therefor. The technical solution thereof is the catalyst comprising the following components in parts by mass: 50-80 parts of titanium dioxide, 2-15 parts of high-viscosity kaolin, 2-10 parts of glass fibers, 2-10 parts of carbon fibers, 2-15 parts of a plasticizer, 0.5-2 parts of ammonium heptamolybdate, 0.5-2 parts of ammonium metavanadate, and 10-30 parts of water. In the present invention, the high-viscosity kaolin is prepared, and in combination with the subsequent high-temperature coating process, the adhesive force between a catalyst slurry and a stainless steel screen plate is greatly improved, thereby enhancing the stability of the catalyst, prolonging the service life of the catalyst, and improving the reaction efficiency of the catalytic.