7results about How to "Avoid deep oxidation" patented technology

The invention discloses a supported catalyst with a strong-coupling bimetallic nanoparticle active center, a preparation method of the supported catalyst and application of the supported catalyst in selective dehydrogenation of isopropanol. The preparation method comprises the following steps: mixing a dimethyl sulfoxide solution containing acetylacetone metal salt A and acetylacetone metal salt B with a dimethyl sulfoxide solution containing a carrier powder sample, carrying out ultrasonic treatment to a transparent colloid shape, drying, and roasting to obtain the supported catalyst with the strong coupling bimetallic nanoparticle active center. The prepared catalyst shows excellent catalytic efficiency in the selective dehydrogenation reaction of isopropanol, the yield of acetone in an isopropanol dehydrogenation product can be kept at 90% or above at a wide temperature window (100-200 DEG C), and the acetone generation rate of the catalyst at 200 DEG C is increased by 10.5 times compared with that of a traditional Pd-based catalyst.

The invention relates to a post-treatment method for a mercury-based II-VI group nanocrystal with a protective layer formed by chemical oxidation, and solves the problems of poor stability and photoelectric property degradation of the mercury-based II-VI group nanocrystal caused by surface oxidation, ligand desorption and environmental sensitivity. An oxide protection layer with the thickness of 1-3 nm is formed on the surface of the nanocrystal, the long-term stability and the photoelectric property of the nanocrystal are improved, and the method comprises the specific steps of centrifugal purification of the nanocrystal, preparation of an oxidizing agent solution, controllable oxidation reaction, functional ligand surface modification and purification treatment. The oxidation layer is ensured to be compact and stable by accurately adjusting the concentration of the oxidant, the reaction temperature and the reaction time. According to the method, oxygen and moisture permeation is effectively blocked, surface defects are reduced, the quantum yield and the photoelectric property are improved, and the method is widely applied to the fields of post-treatment of mercury-based II-VI group nanocrystals and photoelectric devices.

This invention relates to a method for the coupling production of C2 hydrocarbons and benzene from methane via carbon dioxide oxidation, belonging to the field of chemical production technology. Specifically, a mixture of methane and carbon dioxide is passed through a reactor equipped with a catalyst to produce C2 hydrocarbons and benzene, with carbon monoxide and water as byproducts. In this method, the selective production of C2 hydrocarbons and benzene is achieved by changing the type and composition of the catalyst and simultaneously adjusting the reaction conditions. This invention features a short process flow, simple operation, and uses an inexpensive, readily available, and stable catalyst, making it easy to scale up industrially and showing promising prospects for industrial application.

The application discloses a kind of preparation and application of g-C3N4 / VPO photothermal catalytic material, its characteristics are that g-C3N4 nanosheet is assembled with VPO nanosheet using electrostatic assembly strategy, and photothermal catalytic material of general formula g-C3N4 / VPO is obtained.Under photothermal condition, g-C3N4 / VPO is used as photothermal catalyst, and high-efficiency selective oxidation of n-butane is carried out to prepare maleic anhydride at low temperature.Compared with prior art, the application has the advantages of low reaction temperature, high selectivity, mild preparation conditions, large-scale preparation, green reaction, and wide application prospect.

The invention discloses a method for catalyzing O2 to oxidize hydrocarbon compounds by metalloporphyrin based on continuous flow tubular reaction without tail gas emission, which comprises the following steps: feeding a raw material solution containing a catalyst and O2 into a 1 # mixer, feeding the mixed solution into a reaction pipeline to carry out catalytic oxidation reaction, uniformly arranging n 2 # mixers in the reaction pipeline at intervals, and n being an integer greater than or equal to 1; and cooling the reaction liquid after the reaction, and introducing the cooled reaction liquid into a gas-liquid separator for gas-liquid separation to obtain a reaction mixture containing part of oxidation products alcohol and ketone. According to the hydrocarbon continuous flow oxidation method provided by the invention, the yield of partial oxidation products (alcohol and ketone) is high, and the selectivity is high. Compared with the traditional kettle reaction, the continuous flow reaction involved in the invention is more efficient and safer. Compared with other continuous flow tubular reactions, the continuous flow reaction involved in the invention has no tail gas emission and is more environment-friendly. The method is a safe, efficient and environment-friendly hydrocarbon oxidation method.

The invention discloses a supported catalyst with a sub-nanocluster active center, a preparation method and an application of the supported catalyst in selective dehydrogenation of isopropanol, the preparation method comprises the following steps: uniformly mixing a noble metal precursor solution with a carrier, carrying out rotary evaporation treatment by adopting a step-by-step depressurization vacuum extraction method, then carrying out primary roasting, and carrying out secondary roasting to obtain the supported catalyst with the sub-nanocluster active center. Powder is obtained; performing plasma discharge treatment on the powder under mixed gas of hydrogen and argon to obtain a sample; and carrying out secondary roasting on the sample. The selective activation of C-H bonds of isopropanol molecules and the rapid desorption of acetone reaction intermediates are synergistically realized through the strong coupling effect and the synergistic catalysis effect among metal atoms with uniform coordination structures on sub-nanocluster sites, so that the deep oxidation of the isopropanol molecules is avoided. The catalyst shows excellent catalytic efficiency in an isopropanol selective dehydrogenation reaction, and the yield of acetone in an isopropanol dehydrogenation product can be kept at 90% or above under a wide temperature window (100-200 DEG C).

This invention provides a method for preparing the selective oxidation catalyst FeMo@ZSM-22. The method includes: preparing a mixed metal salt solution by dissolving soluble molybdate and soluble iron salt; ultrasonically dispersing ZSM-22 molecular sieve powder in deionized water to obtain a molecular sieve suspension; slowly adding the mixed metal salt solution dropwise to the molecular sieve suspension under rapid stirring, and adding a precipitant to adjust the pH to 2.0-5.0; and obtaining the FeMo@ZSM-22 catalyst after microwave aging, washing, drying, and calcination. This invention incorporates ZSM-22 molecular sieve in situ during the co-precipitation synthesis of the FeMo catalyst, achieving a high degree of synergy between the redox sites (FeMo) and the weakly acidic sites (ZSM-22) at the nanoscale. The resulting catalyst is used for the direct selective oxidation of dimethyl ether to formaldehyde, not only overcoming the seesaw effect between activity and selectivity in traditional pure metal oxide catalysts, but also exhibiting extremely low preparation cost, good long-term anti-coking stability, and promising prospects for large-scale industrial production.