134results about How to "Reduced catalytic efficiency" patented technology

Fuel cells are described and contain a gas diffusion electrode, a gas diffusion counter-electrode, an electrolyte membrane located between the electrode and counter-electrode. The electrode or counter-electrode or both contain at least one modified carbon product. The electrolyte membrane can also or alternatively contain modified carbon products as well. The modified carbon product is a carbon product having attached at least one organic group. Preferably the organic group is a proton conducting group and/or an electron conducting group. The present invention preferably permits the elimination of fluoropolymer binder in the active or catalyst layer and further preferably leads to a thinner active layer and/or a thinner electrolyte membrane. Other uses and advantages are also described.

Methods and systems are provided for mitigating engine pre-ignition based on a feed-forward likelihood of pre-ignition and feedback from a pre-ignition event. In response to an indication of pre-ignition, a cylinder may be enriched while an engine load is limited. The enrichment may be followed by an enleanment to restore exhaust catalyst feed-gas oxygen levels. The mitigating steps may be adjusted based on engine operating conditions, a pre-ignition count, as well as the nature of the pre-ignition.

The present invention is directed to variant squalene synthase enzymes, including Saccharomyces cerevisiae squalene synthase enzymes, and to nucleic acid molecules encoding these variant enzymes. These variant enzymes produce squalene at a lower rate than the wild-type enzyme, allowing more farnesyl pyrophosphate to be utilized for production of isoprenoid compounds, while still producing sufficient squalene to allow the S. cerevisiae cells to grow without the requirement for supplementation by sterols such as ergosterol. These variant enzymes, therefore, are highly suitable for the efficient production of isoprenoids.

The invention relates to a preparation method of a catalyst material for hydrogen production by virtue of electrolysis of water. The preparation method comprises the steps of soaking graphite carbon nanostructure-graphene composite carbon paper in a precursor solution of molybdenum and sulfur, carrying out a hydrothermal reaction or a solvothermal reaction, and then repeatedly washing to obtain a molybdenum sulfide and graphite carbon nanostructure-graphene composite carbon paper material, namely the catalyst material. Compared with the prior art, the catalyst material can be directly used as a catalytic electrode material for hydrogen production by virtue of electrolysis of water without glassy carbon electrode coating treatment; the preparation method is green and safe, simple in process and low in raw material cost, can realize large-scale continuous production and has wide application prospect in the field of hydrogen production by virtue of electrolysis of water.

The invention discloses a preparation method for titanium dioxide serving as a catalyst carrier. The preparation method comprises the following steps of: dispersing metatitanic acid serving as a raw material by pulping, and adjusting until the concentration of the slurry is 12 to 26 mass percent based on titanium dioxide (TiO2); adding ammonia water into the slurry, and adjusting the pH value to be between 6.0 and 9.0; filtering and dehydrating to obtain a blocky filter cake; mechanically crushing the blocky filter cake; drying and calcining the crushed filter cake at 200 to 560 DEG C for 6 hours; and grinding the calcined material in a kiln to obtain a titanium dioxide product which serves as a denitration catalyst carrier. By the preparation method, the manufacturing cost is low, the process is simple, the prepared product has the advantages of large specific area, high surface chemical activity and high processability, and the prepared final product is high in catalytic efficiency.

A fuel control approach that compensates for time delays to increase exhaust gas sensor feedback response speed.

The invention discloses a preparation method of a catalyst for synthesizing diphenyl carbonate, and belongs to the technical field of catalyst synthesis. The catalyst is obtained by modifying a transition metal oxide by poly-electrolyte until the transition metal oxide is positively or negatively charged, and wrapping a layer of metal organic framework (MOFs) on the outer surface of the transition metal oxide by an electrostatic layer-by-layer self-assembling method, namely the oxide is used as a core, and the MOFs is used as a shell; the catalyst is MalphaObeta@MOFs fort short (M is one of transition metal elements, and alpha and beta are valences). The catalyst is enabled to react with ammonia chloride with a certain concentration to convert the core MalphaObeta into corresponding chloramine salt M(NH3)nClbeta (n is the number of ammonia molecules and is equal to 1 to 8); after ammonia is removed by low-temperature roasting, the catalyst MClbeta@MOFs is obtained. The catalyst can be used in a system for generating diphenyl carbonate by transesterification between urea or carbamic acid ester and phenol; new coordination adsorption is performed on the catalyst and ammonia generated by the reaction system to push the reaction to move rightwards; the yield of a diphenyl carbonate product is up to 90 percent or above; after the catalyst is used for 5 times, the catalysis effect is still good.

The invention relates to a method for measuring octyl phenol by virtue of an electrochemical sensor. The method comprises the following steps: dispersing Ni-g-C3N4 serving as a modifier into an N,N-dimethylformamide solution, coating dropwise the surface of a glassy carbon electrode with the mixed solution, and drying the glassy carbon electrode to obtain a modified electrode; placing the obtained modified electrode into a solution containing a supporting electrolyte solution and a substance to be measured; performing cyclic voltammetry scanning or differential pulse scanning under the irradiation of an infrared lamp, and determining that octyl phenol exists in the substance to be measured if an electrocatalytic oxidation peak appears. The method has the beneficial effects that the surface of the glassy carbon electrode is modified with a nanometer material with an intensified current signal, and the electrochemical sensor is constructed by the specificity recognition of the nanometer material and octyl phenol; g-C3N4 is doped with other elements or compounds, so that the band gap of g-C3N4 can be changed, the interaction of interlayer atoms can be enhanced, the response duration can be prolonged, and photocatalysis efficiency can be improved.

Various systems and methods are provided for an exhaust gas treatment system. In one example, a system includes an exhaust gas treatment device and a wire wrapped around an exterior circumference of the exhaust gas treatment device. Continuity of the wire is monitored such that degradation of the wire due to degradation of the exhaust gas treatment device is indicated.

The invention relates to a method for preparing hexafluorobutadiene from iodine and chlorine. The method comprises the following steps: preparing a metal coordinated ionic liquid solvent, and reacting iodine with chlorine to prepare iodine monochloride; reacting iodine monochloride with chlorotrifluoroethylene in the presence of the metal coordinated ionic liquid solvent to prepare 1,2-dichloro-2-iodo-1,1,2-trifluoroethane; carrying out a reaction on the 1,2-dichloro-2-iodo-1,1,2-trifluoroethane in the presence of the metal coordinated ionic liquid solvent under the catalysis of zinc powder to obtain 1,2,3,4-tetrachloro-1,1,2,3,4,4-hexafluorobutane; and reacting the 1,2,3,4-tetrachloro-1,1,2,3,4,4-hexafluorobutane with zinc powder in the presence of the metal coordinated ionic liquid solvent to generate hexafluorobutadiene.

The invention belongs to the technical field of water treatment, and provides a photocatalytic separation film for water treatment and a preparation method. The method includes the steps that nano TiO2 and nano ZnO are generated in situ in the synthesis process of tertiary butyl thio[4]calixarene, then the nano TiO2 and the nano ZnO are compounded with graphene, a nano TiO2-nano ZnO-calixarene -graphene composite photocatalyst is prepared and further added into a polyether sulfone spinning solution, and the photocatalytic hollow fiber separation film is prepared through spinning. Compared witha traditional method, by means of the prepared photocatalytic separation film, the problem of film contamination in the film separation technology and the problem about nano powder recovery in the photocatalysis technology are solved at the same time, the utilization rate of visible light is high, the photocatalysis efficiency is high, and a catalyst can be evenly dispersed.

The present invention provides a method for preparing wrinkle-free graphene. The method comprises the following steps of: S1: providing a catalyzation substrate; performing ion implantation in a preset region of a surface of the catalyzation substrate to damage catalytic performance of the implantation region and to form a plurality of separate non-implantation units on the surface of the catalyzation substrate; and S2: putting the catalyzation substrate in a growth chamber; heating the catalyzation substrate to a preset temperature; introducing a carbon source to the growth chamber; and growing a plurality of separate wrinkle-free graphene units on the surface of the catalyzation substrate. According to the method provided by the present invention, not only high-quality graphene units with no wrinkle or low wrinkle density can be obtained, but also graphene units in a particular shape can be obtained by controlling the region in which ions are implanted, thereby meeting various device application demands.

The invention relates to a VOCs catalyst for synergistic catalytic oxidation of ultraviolet-light self-excited ozone and a preparation method and application thereof. Alkali-free wax-free glass fiberis taken and cooked with a nitric acid solution, then is washed with ionized water to be neutral, and is dried; tetrabutyl titanate is used as a precursor and is mixed with anhydrous ethanol to obtaina solution A; deionized water, zirconium oxychloride and acetic acid are dissolved in ethanol, and a solution B is obtained by stirring; the solution A is evenly stirred and then the solution B is added to get a light yellow precursor C; the glass fiber is soaked in the light yellow precursor C, drying is performed after impregnation, ageing is performed at room temperature, vacuum drying is executed in a vaccum drying oven, roasting is carried out in a muffle furnace, and natural cooling is executed to room temperature to obtain Zr-Ti supported glass fiber; a solution D is obtained by mixingthe manganese nitrate, ethanol, acetic acid and deionized water; the Zr-Ti supported glass fiber is impregnated in solution D, aged, dried and roasted to obtain the VOCs catalyst for synergistic catalytic oxidation of ultraviolet-light self-excited ozone.

The invention provides a preparation method of silica gel column supported meso-porous biochar solid sulfonic acid (SiO2-BC-SO3H) from wood fiber biomass, and a method using the silica gel column supported meso-porous biochar solid sulfonic acid to catalyze sucrose hydrolysis for preparing glucose. The preparation method of the SiO2-BC-SO3H comprises the following steps: biomass heat carbonization or concentrated sulfuric acid dehydration carbonization, boiling water swelling, acidic silica sol intercalation, heating (350 DEG C) dehydration in nitrogen, and concentrated sulfuric acid sulfonation. The silica gel content of the SiO2-BC-SO3H prepared through the steps is about 15 wt%, the sulfonic group density is 0.9 mmol/g or above, and the SiO2-BC-SO3H has an interlayer meso-porous structure. The SiO2-BC-SO3H has better catalysis activity and better reusability than non-porous biochar solid sulfonic acid in the catalysis of the sucrose hydrolysis reaction.

The invention discloses a graphene oxide supported ruthenium catalyst as well as a preparation method and application thereof, and belongs to the crossing field of organic chemistry and material chemistry. According to the present invention, graphene oxide is adopted as a carrier to load a supported catalyst containing metal ruthenium, the catalyst is used for catalyzing the reaction between the alcohol and the alcohol to synthesize the substituted ketone compound, the test result shows that the catalyst provides the high catalytic activity for the reaction, and the catalyst can be recycled; and meanwhile, the catalyst can also be used for synthesizing bisphenol F under mild reaction conditions, and accords with the ideas of atom economy and green chemistry development.

The invention provides crosslinking hyaluronic acid gel resisting hydrolysis of hyaluronidase, and relates to the crosslinking hyaluronic acid gel, natural flavocoenzyme and derivatives of the naturalflavocoenzyme. The derivatives include riboflavin, isoalloxazine, 7-M-8-C, 7-B-8-M, 7-M-8-B, 7-C-8-E and 7,8-D. The invention further provides a method for utilizing the natural flavocoenzyme and thederivatives of the natural flavocoenzyme for lowering the activity of the hyaluronidase, effectively prolonging the maintaining time of the crosslinking hyaluronic acid gel, and effectively improvingthe plasticity effect of the crosslinking hyaluronic acid gel. By means of the method, in an experiment of in-vitro enzymolysis of crosslinking hyaluronic acid, the catalysis efficiency of the hyaluronidase is lowered by 50% or above. The crosslinking hyaluronic acid gel has a large application potential and shows great economic benefits.

The invention relates to a preparation method and application of a core-shell catalyst which adopts a transition metal salt as a core and a nano-molecular sieve as a shell, and belongs to the technical field of catalysts. The preparation method comprises the steps of: firstly preparing transition metal oxide or transition metal hydroxide, performing surface modification on the oxide and hydroxideof transition metal by using a polyelectrolyte so as to make the surface of the oxide and hydroxide of the transition metal positively or negatively charged, coating the surface of the modified oxideand hydroxide of the transition metal with a layer of silicallite-1 type nano-molecular sieve seed crystals by using an electrostatic layer-by-layer self-assembly method, then performing secondary growth of a silicallite-1 type molecular sieve membrane on the silicallite-1 type nano-molecular sieve seed crystals so as to obtain a solid B which adopts the transition metal oxide or transition metalhydroxide as the core and the silicallite-1 type molecular sieve as a shell, performing a solid-phase reaction between with the solid B and ammonium salt solid powder so as to obtain Malpha(NH3)nXbeta@silicallite-1, Malpha(NH3)nXbeta@silicallite-1, and performing low temperature calcination to obtain the core-shell catalyst MalphaXbeat@silicallite-1. Through the core-shell catalyst MalphaXbeat@silicallite-1, synthesis of organic carbonates can be catalyzed.

The invention provides an automobile exhaust catalyst which comprises a front end carrier and a rear end carrier. The automobile exhaust catalyst is characterized in that the front end carrier is in an oval runway shape, and the mesh number of the carrier is 3/600. A front end coating coats the front end carrier, and a single layer of palladium coats the front end coating. The rear end carrier is in an oval runway shape, the mesh number of the carrier is 4/400, a rear end coating coats the rear end carrier, and precious metal coats the rear end coating in a partitioned mode. The invention further provides a catalytic converter which is low in initiation temperature, short in initiation time, high in catalytic conversion efficiency, simple in structure, and low in cost. Meanwhile, backpressure loss of the catalytic converter is further reduced, engine power is guaranteed, and reduction of oil consumption of an automobile is facilitated.

The invention provides a core-shell-structured hierarchical iron/copper bimetallic Fenton catalyst and a preparation method and application thereof, belonging to the technical field of degradation treatment of organic pollutants in wastewater in virtue of Fenton catalysts. The preparation method comprises the following steps: adding zeolite into a ferric iron salt solution, carrying out stirring for a reaction, then carrying out centrifugal washing with deionized water, and performing freeze drying to obtain an isolated iron catalyst; and then adding the obtained isolated iron catalyst into abivalent copper salt solution, carrying out a stirring reaction for a certain period of time, then carrying out centrifugal washing with deionized water, and carrying out freeze drying to obtain the core-shell-structured hierarchical iron/copper bimetallic Fenton catalyst. The catalyst prepared in the invention has a wide pH application range, can be used for Fenton oxidation degradation of organic pollutants in high-pH environmental sewage and has excellent catalytic performance and reusability; and an effective method for is provided for the application of the bimetallic Fenton catalyst anddegradation treatment of sewage.

The invention discloses a preparing method and application of a core-shell material catalyst. The catalyst nuclear material is obtained after the surface of chlorine ammonium salt is coated with a layer of zeolite membrane in an electrostatic mode with the layer by layer self-assembly method under the electrostatic interaction of positive and negative polyelectrolytes, the target product catalyst obtained after ammonia gas is separated out through low-temperature roasting can be used in a system for generating diphenyl carbonate through transesterification between urea or carbamic acid ester and phenol, complex adsorption can be achieved between the catalyst and ammonia gas generated by the reaction system so as to push reaction to move rightwards, the yield of diphenyl carbonate is over 90%, a good catalytic effect can still be realized after five times of usage, separation and recovery are easy, and selectivity is high.

The invention discloses an amphiphilic Lindqvist-type polyacid TiO2 composite nanofiber. A preparation method of the nanofiber comprises the following steps: (1) under magnetic stirring, adding a cetyltrimethylammonium bromide water solution into a Na2MoO6.2H2O water solution acidized by hydrochloric acid, heating, filtering, washing with water and diethyl ether, and drying; (2) dissolving butyl titanate and polyvinylpyrrolidone into a mixed solvent of N,N-dimethylformamide, glacial acetic acid and diacetone, and preparing a TiO2 nanofiber by virtue of an electrostatic spinning method; and (3)dispersing the TiO2 nanofiber into ethanol, and stirring, so as to obtain a solution A, dissolving surfactant-packaged Lindqvist-type polyacid into ethanol, stirring to obtain a solution B, slowly dropwise adding the solution B into the solution A, stirring, washing with water and ethanol, and carrying out vacuum drying, so as to obtain the composite nanofiber. The preparation method is simple; the agglomeration problem of polyacid is effectively solved; the composite nanofiber is easy to separate and recycle; and an extraction catalytic oxidation desulfurization system is formed by hydrogenperoxide and ionic liquid [Bmim]PF6, so that the utilization rate of hydrogen peroxide is increased, the desulfurization efficiency is high, and the reusability is good.

The invention discloses a preparation method and application of a cerium dioxide nanowire, and belongs to the technical field of material preparation and environmental governance. The method comprises the following steps: carrying out a strong alkaline hydrothermal reaction on an aqueous solution of a molybdenum source and an aqueous solution of a cerium source to generate a mixture of a cerium oxide precursor and the molybdenum source, and uniformly mixing the mixture through hydrothermal stirring; and finally, carrying out high-temperature calcination in an air atmosphere to obtain the cerium dioxide nanowire. After cerium dioxide is modified with molybdenum, the morphology of cerium dioxide can be changed, the yield of carbon dioxide can be increased, precious metal can be replaced to achieve the purpose of increasing the yield of carbon dioxide, and the cost is remarkably reduced. The method has the advantages of simple operation, easily available raw materials, low cost, low energy consumption and the like; the stability is good, the activity is high, and the efficiency of photo-thermal catalytic combustion of volatile organic compounds is high.

The invention discloses a catalyst compound capable of degrading formaldehyde, dry-powdered emulsion paint and a preparation method thereof. The compound is prepared from organic emulsion particles, noble metal catalyst particles and inorganic solid protective agent particles, and is prepared by a spray drying method; the noble metal catalyst particles and the inorganic solid protective agent particles can be embedded into the organic emulsion particles to a certain extent and cannot be separated from the organic emulsion particles so as to form protection layers on the surfaces of the organic emulsion particles; therefore, adhesion of the organic emulsion particles during spray drying is avoided, uniform dispersion of the catalyst particles in a paint film forming process is facilitated, and the catalysis efficiency is improved. By means of the spray drying method, volatilizable components in the organic emulsion particles can be removed; meanwhile, the emulsion paint disclosed by the invention is in a solid state, so that no preservatives or antifreezing agents is added, the VOC value of the system is reduced, and packing and transportation are facilitated.