48 results about "Catalyst degradation" patented technology

The invention belongs to the technical field of organic wastewater treatment, and relates to an iron-based heterogeneous Fenton catalyst as well as a preparation method and application thereof. The invention aims to solve the technical problems that in the prior art, a heterogeneous Fenton catalyst needs an acidic condition to degrade organic pollutants, and under the acidic condition, the conversion rate of Fe (II) / Fe (III) is low, and the reaction needs a long time, so that the degradation efficiency is low. The invention provides an iron-based heterogeneous Fenton catalyst which comprises iron phosphide and Schwertmannite, the loading proportion of the iron phosphide on the catalyst is 10%-18%, and the catalyst promotes Fe (II) regeneration and is good in stability and high in catalytic performance. The invention also provides a preparation method of the catalyst, which comprises the following steps: adding iron phosphide into pure water, adding ferrous sulfate and / or a hydrate of ferrous sulfate into the obtained iron phosphide suspension, reacting, collecting precipitate, washing, and freeze-drying to obtain the catalyst. The invention further provides application of the iron-based heterogeneous Fenton catalyst, when the iron-based heterogeneous Fenton catalyst is used for degrading organic pollutants, acidic conditions are not needed, the catalytic performance is improved, and the degradation efficiency is improved.

This invention belongs to the field of environmental chemical catalytic water treatment technology and discloses a method for preparing a Cu2O / black phosphorus catalyst for removing antibiotics from water. Using Cu2O and black phosphorus (BP) as precursor reactants, a series of Cu2O / BP composite photocatalysts were prepared. The BP catalyst was prepared by a simple hydrothermal method. Then, Cu(NO3)2·3H2O and BP were calcined in varying proportions to form the composite Cu2O / BP photocatalysts. Analysis revealed that the Cu2O was loaded onto the BP layer, forming a composite structure. The prepared catalysts were used to degrade levofloxacin hydrochloride under visible light, and the catalytic activity of the composite photocatalysts was evaluated. Results showed that among the photocatalysts with varying Cu2O / BP loadings, 3% and 4% Cu2O / BP exhibited the best photocatalytic degradation performance, achieving a degradation rate of 89% in 3 hours, 2.83 times that of pure BP. This demonstrates the successful preparation of highly efficient composite catalysts.

The present invention provides a catalyst regeneration apparatus and a catalyst regeneration method that can regenerate a degraded catalyst while suppressing a decrease in production efficiency during the production of a predetermined product. [Solution] A catalyst regeneration device for a reactor 3 that produces a predetermined product by catalytic action of catalysts in each reaction tube 2 using a plurality of reaction tubes 2, each filled with catalyst C, while continuing to introduce the raw material gas, the device comprises a catalyst degradation detection unit for detecting whether or not the catalyst C in each of the plurality of reaction tubes 2 has deteriorated, a regeneration gas supply unit 6 capable of supplying a predetermined regeneration gas to each reaction tube 2 for regenerating the deteriorated catalyst C, and a control unit 7 that controls the regeneration gas supply unit to supply regeneration gas to the reaction tube 2 having a catalyst C that has been detected to have deteriorated based on the detection results from the catalyst degradation detection unit.

The invention discloses a binuclear enhanced ethylene selective tetramerization catalytic system and its application, belonging to the field of polymerization catalysts. The catalytic system of the present invention includes ligand a, transition metal compound b and activator c, wherein ligand a is composed of three parts: PNP ligand, PNNP ligand and rigid linking group. The present invention adopts a rigid group with a substituted group to connect PNP and PNNP, suppresses the interaction of the catalyst active center, reduces catalyst degradation and inactivation, and simultaneously passes through the large π bond of the linking group and the ligand skeleton through p-π conjugation, effectively transmits the electronic effect of the substituent on the linking group to the ligand, and has little influence on its steric group effect, thereby achieving the purpose of enhancing the thermal stability of the catalyst and maintaining its good 1-octene selectivity.

A working machine, an oxidation catalyst degradation detection device, an oxidation catalyst degradation detection method, and an oxidation catalyst degradation detection program are provided, which enable a suitable detection of a degradation of an oxidation catalyst. A working machine includes a temperature detecting device for detecting a temperature between an oxidation catalyst and a filter, and a controller. The controller calculates an average of temperatures detected by the temperature detecting device in a regeneration processing of the filter, and calculates a degradation degree of the oxidation catalyst on the basis of the calculated average.

The invention discloses a method for degrading acid orange 7 by using a magnetic biochar-supported catalyst of papermaking sludge, which includes: adding the magnetic biochar-supported catalyst of papermaking sludge into acid orange 7 sewage, adding persulfate to initiate the reaction after adsorption equilibrium, and recovering the magnetic biochar-supported catalyst of papermaking sludge by using a magnet after the reaction ends; the preparation method of the magnetic biochar-supported catalyst of papermaking sludge includes: directly adding the powder obtained by drying papermaking sludge into a Co(NO3)2 solution, continuously stirring and mixing for 1 to 25 hours, separating the solid and liquid, taking the solid for drying and pyrolyzing in an argon atmosphere, then washing and drying again to obtain the magnetic biochar-supported catalyst of papermaking sludge; the magnetic biochar-supported catalyst of papermaking sludge has the following phases: Fe2O3, Co3O4, CaCO3 and Fe3O4.

The invention discloses an anti-reverse electrode, a preparation method thereof and a membrane electrode, and the preparation method of the anti-reverse electrode comprises the following steps: dispersing titanium oxide in isopropanol to obtain a first mixed solution; mixing the first mixed solution with a Nafion resin solution to obtain a second mixed solution, and performing vacuum drying on the second mixed solution to obtain a Nafion resin-titanium oxide compound; putting the Nafion resin-titanium oxide compound and a platinum-carbon catalyst into a ball-milling tank according to a preset proportion, and carrying out ball-milling treatment to obtain mixed slurry; a preset carrier is coated with the mixed slurry in a blade coating mode, an anti-reverse-pole catalyst layer is formed on the preset carrier, and the anti-reverse-pole electrode is obtained. The Nafion resin-titanium oxide compound is introduced, stable perfluorinated sulfonic acid resin and a pore network are constructed, an efficient transmission path can be provided for protons and gas, the influence of catalyst degradation and structure change on performance is reduced, and the overall efficiency of the battery is improved.

The invention discloses a method for preparing a confined iron-based porous carbon catalyst from a compound extracted from printing and dyeing alkali-decrement white mud and application of the confined iron-based porous carbon catalyst. The specific method is as follows: the printing and dyeing alkali-decrement white mud is uniformly dispersed in an organic solvent, filtrate containing terephthalic acid is extracted through oscillation and suction filtration, then ferric trichloride hexahydrate is dropped into the filtrate, and the filtrate is filtered to obtain the confined iron-based porous carbon catalyst. Performing stirring hydrolysis and hydrothermal reaction to synthesize an MIL-101 (Fe)-W precursor, and performing pyrolysis in an inert atmosphere to obtain the confined iron-based porous carbon catalyst Fe (at) C-W. The catalyst has a high specific surface area and a confinement structure, and the prepared catalyst can be used for activating hydrogen peroxide to degrade organic pollutants. The industrial waste is recycled, and the catalyst is high in degradation efficiency, suitable for a wide pH range and good in stability.

The application relates to application of an AgBiS2 photothermal catalyst in degradation of polyester, and belongs to the field of resourceful treatment of waste polymer materials and solar energy catalysis technology. The application of the AgBiS2 photothermal catalyst in degradation of polyester comprises the following steps: mixing polyester, an alcohol solvent and the AgBiS2 photothermal catalyst, and completing degradation of the polyester after reaction under light. The application of the AgBiS2 photothermal catalyst in degradation of polyester can efficiently utilize sunlight to drive chemical recycling of the polyester under mild conditions, efficient depolymerization of PET can be realized under simulated sunlight irradiation, the conversion rate of PET is close to complete, the separation yield of the target monomer BHET reaches 96.2 %, and the feeding amount of the AgBiS2 photothermal catalyst is 1 %. The application of the AgBiS2 photothermal catalyst in degradation of polyester can ensure degradation efficiency while significantly reducing the feeding ratio of the catalyst, and provides a feasible path for on-site resourceful treatment of distributed and small-scale plastic waste.

This invention discloses a membrane electrode testing method and apparatus. The method involves cycling the membrane electrode multiple times, with each cycle including an anolyte voltage cycle durability test and a reverse polarity resistance test, thereby achieving durability testing of the anolyte catalyst layer. The anolyte voltage cycle durability test primarily addresses the impact of vehicle start-stop processes on the membrane electrode; therefore, this method considers the anolyte catalyst degradation caused by start-stop cycles. The reverse polarity resistance test corresponds to hydrogen starvation conditions. In other words, this method and apparatus simultaneously consider both anolyte reverse polarity and anolyte catalyst degradation caused by start-stop cycles, enabling rapid testing of the membrane electrode's lifespan and durability based on the start-stop and reverse polarity processes occurring on the anode side, thus improving test accuracy.

A working machine, an oxidation catalyst degradation detection device, an oxidation catalyst degradation detection method, and an oxidation catalyst degradation detection program are provided, which enable a suitable detection of a degradation of an oxidation catalyst. A working machine includes a temperature detecting device for detecting a temperature between an oxidation catalyst and a filter, and a controller. The controller calculates an average of temperatures detected by the temperature detecting device in a regeneration processing of the filter, and calculates a degradation degree of the oxidation catalyst on the basis of the calculated average.

The invention belongs to the technical field of degradation of rhodamine B by a cobalt-based catalyst, and particularly relates to experimental equipment and a method for degrading rhodamine B by a biomass charcoal modified cobalt-based catalyst. The experimental equipment comprises a catalyst preparation mechanism; the catalyst preparation mechanism is placed at the left end of the table top, and the catalyst preparation mechanism is used for preparing cobalt-based catalysts with different lignin addition amounts; the catalyst preparation mechanism is arranged at the right end of the table top, the solution preparation and adsorption mechanism is arranged at the right end of the catalyst preparation mechanism, the solution preparation and adsorption mechanism is placed at the right end of the table top, and the solution preparation and adsorption mechanism is used for preparing an RhB solution and a PMS solution. The experiment can be more coherent, and multiple complex procedures of the experiment are reduced, so that the experiment speed is increased, and meanwhile, experiment substances can be displayed more clearly.

The invention relates to the technical field of sewage treatment, in particular to a method for degrading organic pollutants by coupling a low-temperature plasma with a nano-catalyst, which comprises the following steps: preparing an MCIN magnetic iron-carbon-based nano-catalyst, respectively dissolving ferric chloride hexahydrate and fumaric acid in ultrapure water, mixing and stirring, carrying out hydrothermal reaction to generate an MIL-88A precursor, and preparing the MCIN magnetic iron-carbon-based nano-catalyst. And carrying out high-temperature calcination in a nitrogen atmosphere to obtain the MCIN catalyst. By preparing the nano-catalyst which has the characteristics of low cost and easy separation and can efficiently utilize active oxygen species and applying the nano-catalyst to a low-temperature plasma-catalyst coupling system, on one hand, the active oxygen species generated by plasma can be more efficiently utilized to realize efficient removal of refractory organic pollutants in wastewater; on the other hand, secondary pollution caused by the fact that a conventional catalyst is difficult to separate is avoided, in addition, the adopted iron-carbon-based catalyst is low in cost, and a coupling system of the plasma and the catalyst is further optimized.

The invention discloses a catalyst for photodegradation of polyurethane, a degradation method, a preparation method and a recovery method. The invention provides a degradation method of polyurethane. The degradation method comprises the following step: irradiating a mixture of a catalyst, a solvent and polyurethane with light. According to the degradation method disclosed by the invention, the polyurethane material can be rapidly degraded in a heterogeneous phase, the time required for degrading the polyurethane material is greatly shortened, the treatment requirement of the polyurethane material is reduced, a bulk material can be directly degraded without disassembling, crushing and dissolving processes, and the material does not need to be crushed into powder and then degraded; and moreover, the conversion rate of waste polyurethane is high, and degradation products only comprise polyhydric alcohols and corresponding organic amines, and are high in purity and easy to separate.

In an apparatus and method for recovering degradation of an anode catalyst, the apparatus increases a hydrogen flow rate supplied to the anode of the operating fuel cell stack above a normal value, estimates a nitrogen concentration of the anode based on the hydrogen concentration of the anode, and pulse-controls an output voltage of the fuel cell stack in response that the nitrogen concentration of the anode reaches a preset value, electrochemically oxidizing carbon monoxide adsorbed on the surface of the anode catalyst.

Catalyst regeneration equipment for regenerating a catalyst that has been degraded due to a catalytic action, while a predetermined source gas is being continuously introduced, in a reactor including a plurality of reaction tubes each being filled with the catalyst, the reactor generating a predetermined product through the catalytic action of the catalyst in each of the plurality of reaction tubes, the catalyst regeneration equipment including: a catalyst degradation detection unit configured to detect presence or absence of degradation of the catalyst in every one of the plurality of reaction tubes; a regeneration gas supply unit capable of supplying a predetermined regeneration gas for regenerating a degraded catalyst to every one of the plurality of reaction tubes; and a controller configured to control the regeneration gas supply unit to supply the regeneration gas to a reaction tube including the catalyst in which the degradation has been detected, based on a detection result by the catalyst degradation detection unit.

The application provides a bismuth oxide carbonate photocatalyst and a preparation method and application thereof, the bismuth oxide carbonate photocatalyst is prepared through a hydrothermal auxiliary co-precipitation strategy, has high efficient catalytic degradation performance on organic dyes under visible light conditions, and can be suitable for degradation of pollutants in complex water bodies; and the halogen element introduced in the application can obviously enhance the photocatalytic performance of the bismuth oxide carbonate photocatalyst on degradation of organic pollutants, can eliminate the organic pollutants in water bodies at an extremely fast speed, and has a wide applicable prospect in the field of wastewater treatment.

The invention relates to the technical field of unsymmetrical dimethylhydrazine degradation, and provides nitrogen-doped graphene oxide and application of the nitrogen-doped graphene oxide in activation of unsymmetrical dimethylhydrazine in a PDS degradation environment in order to solve the problem of how to efficiently activate PDS to degrade unsymmetrical dimethylhydrazine. The preparation method comprises the following steps: step 1, putting a graphene oxide solution into a beaker, weighing urea, putting the graphene oxide solution and the urea into the beaker, uniformly stirring with a glass rod, and pouring into a porcelain boat; and 2, putting the porcelain boat into a tubular furnace, introducing nitrogen to exhaust oxygen in the boat, carrying out heat treatment, naturally cooling, and taking out the porcelain boat to obtain a fired material, namely the nitrogen-doped graphene oxide, and further grinding the nitrogen-doped graphene oxide into powder. The nitrogen-doped graphene oxide is combined with PDS, and the nitrogen-doped graphene oxide is used for preparing a UDMH degradation material. According to the prepared catalyst, the degradation rate is greatly increased, the degradation rate is increased along with increase of the adding amount, and the degradation rate of the catalyst with the concentration being 0.4 g / L is the highest and is 97.18%.

This invention relates to a method for preparing and applying a metal atom-supported reduced graphene oxide catalyst, specifically a method for preparing and applying a metal atom-supported reduced graphene oxide catalyst. The invention aims to address the technical problems of high energy consumption, high cost, and easy secondary pollution associated with existing catalysts for the degradation of organic pollutants. This invention involves in-situ growth of transition metals on the GO surface to dope the ZIF-8 precursor, effectively improving the interfacial bonding between the precursor and the carbon support, and preventing the loss or migration of active components during subsequent pyrolysis. During pyrolysis and carbonization, the M-ZIF-8 precursor decomposes to form a nitrogen-containing carbon framework, and the transition metal species are supported on the reduced graphene oxide support in an atomically dispersed or highly dispersed form. The resulting catalyst possesses abundant active sites and excellent electron transport properties, and can be applied in electrocatalysis and the degradation of organic pollutants.

Disclosed in the present invention are a method for preparing a double-anion catalyst and the use thereof in the catalytic degradation of a polyurethane material. The method comprises: dissolving a metal salt in deionized water to prepare a metal salt solution; taking a nitrogen heterocyclic compound containing hydroxyl or amino as a substrate in a reactor, adding the metal salt solution in a dropwise manner into the reactor, and performing condensation reflux at 60°C-150°C for 1-8 h; adding an amine compound in a dropwise manner, reacting the mixture after the dropwise addition has finished, and performing a vacuum filtration treatment after the reaction has finished, so as to obtain a filtrate; and evaporating the filtrate and drying the product to obtain a double-anion catalyst. The basic physical properties, such as hydroxyl value, amine value and viscosity, of a recovered polyol obtained via degradation by means of the catalyst of the present invention are substantially equivalent to those of the raw material polyol, and the recovered polyol can partially replace the raw material polyol for preparing a flexible polyurethane foam.

The invention provides a methanol synthesis process with low recycle ratio and low energy consumption, and belongs to the technical field of methanol synthesis. In the methanol synthesis process, the hydrogen-carbon ratio of the inlet gas can dynamically adjust the reaction load of the two-stage synthesis tower to adapt to different life stages of the catalyst, and the efficient reaction is maintained, so that the recycle ratio and the energy consumption are reduced. The two-stage methanol synthesis reaction is adopted, and crude methanol and water generated in the reaction are removed in time, so that the degradation rate of the catalyst is reduced, and the overall operation stability is improved; meanwhile, the primary reaction gas enters the secondary methanol synthesis tower after crude methanol and water are separated, so that the reaction driving force of the secondary methanol synthesis tower is improved, the conversion per pass is improved, and the recycle ratio is reduced. The methanol synthesis process provided by the invention is suitable for a large-scale methanol production device of 2 million tons per year or more, and is also suitable for a CO2 hydrogenation methanol preparation process in the current green methanol industry.

This invention proposes an AOP water-catalyst degradation and separation food purification machine, belonging to the field of food purification machines. The invention includes a purification machine component, a draining component installed vertically within the purification machine component, a circulation component located at the rear of the purification machine component for circulation, and a drainage component for drainage. The purification machine component includes: a purification chamber; a vertical partition fixed in the middle of the purification chamber; and horizontal support plates welded to the left and right sides of the vertical partition, the horizontal support plates dividing the purification chamber into a cleaning chamber and a return water chamber. The draining component includes: a drain basket body located above the horizontal support plates; and the drainage component. This invention, through the drainage component, simultaneously pushes the entire drain basket body upwards during drainage. When the drain basket body is removed, the water level in the cleaning chamber simultaneously decreases, thereby preventing wastewater from splashing out when the drain basket body is removed.

The present invention aims to provide a method for producing olefins using waste plastic raw materials, which enables sufficient catalyst regeneration while suppressing catalyst degradation. [Solution] A method for producing olefins, comprising: a thermal decomposition step of thermally decomposing a waste plastic raw material containing polyolefin to obtain a hydrocarbon flow; a crude olefin production step of supplying the hydrocarbon flow to a catalytic cracking apparatus that decomposes hydrocarbons by contacting a catalyst containing zeolite with hydrocarbons to obtain crude olefins; a separation step of separating olefins having 2 to 4 carbon atoms from the crude olefins; a hot air generation step of generating hot air containing oxygen gas using a hot air generator; and a catalyst regeneration step of supplying the hot air to a catalyst regeneration apparatus that regenerates a catalyst by heating, regenerating the catalyst used in the crude olefin production step with the hot air, and returning the regenerated catalyst to the catalytic cracking apparatus.

The present invention belongs to the technical field of environmental chemical photocatalytic water treatment, and discloses a preparation method and application of a CoO / black phosphorus catalyst. A series of CoO / BP composite photocatalysts are prepared using CoO and Black Phosphoru (BP) as precursor reactants. The BP catalyst is prepared by a simple hydrothermal method, and then Co(CH3COO)2·4H2O and BP are calcined in different proportions to generate a composite CoO / BP photocatalyst. It is analyzed that CoO has been loaded onto the BP layer and a composite structure has been formed. Under visible light conditions, tetracycline hydrochloride is degraded using each of the prepared catalysts, and the catalytic activity of the composite photocatalyst is observed. The results show that among the photocatalysts with different loading amounts of CoO / BP, 50%-CoO / BP has the best photocatalytic degradation effect, and the degradation rate in 4 hours reaches 86.55%, which is 7.76 times and 2.06 times the degradation rates of pure CoO and BP, respectively. This shows that the present invention successfully prepares a highly efficient composite catalyst.

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 invention discloses a process for photocatalytic treatment of coal gangue organic matters by Ce and Yb co-doped nano TiO2. The process specifically comprises the following steps: S1, preparation of a catalyst; s2, coal gangue treatment: preparing a suspension from a Ce / Yb-TiO2 composite catalyst, uniformly spraying the suspension on the surface of the coal gangue, irradiating by using natural light or an auxiliary LED light source, and exciting a photocatalytic reaction; s3, a pollutant degradation path. The invention relates to the technical field of environmental governance and materials. According to the process for photocatalytic treatment of the coal gangue organic matter through Ce and Yb co-doped nano TiO2, efficient broad-spectrum photoresponse is achieved, the light absorption range is expanded to visible light (400-600 nm) through Ce / Yb co-doping, the quantum efficiency is improved by 40%, day-night continuous catalysis is achieved, after a long afterglow material is compounded, the degradation efficiency at night reaches 60% of that in the daytime, stability is high, the degradation rate of the catalyst is still kept 90% or above after 10 times of recycling, and the degradation rate of the catalyst is still kept 90% or above. No chemical reagent is added, byproducts are only CO2 and H2O, secondary pollution is avoided, the raw material cost is reduced by 30%, and the method is suitable for large-scale coal gangue storage yard treatment.

The present invention discloses a heterogeneous catalyst based on tourmaline composite material and its preparation and application, belonging to the fields of inorganic nanomaterials and environment. In this application, a CMT heterogeneous catalyst is prepared by compounding copper molybdate, manganese dioxide and tourmaline. Tourmaline can be used as a Fenton-like reagent to activate PMS to promote the generation of reactive free radicals. Copper molybdate and manganese dioxide have excellent photocatalytic activity. Based on this, the prepared composite material can produce a synergistic effect in the visible light irradiation and PMS activation system; by reasonably compounding copper molybdate with wide / narrow band gaps and manganese dioxide coupling, a CMT heterojunction with a matching band gap structure is prepared, and the light absorption threshold and energy band structure of the photocatalyst are effectively adjusted, improving the mobility of photo-generated carriers and reducing the recombination of photo-generated electrons and holes, and enhancing the photocatalytic activity of the semiconductor material; using this catalyst to degrade water pollutants, the removal rate of 50 mg / L of tetracycline hydrochloride reaches 93.48%.

A preparation method of a dual-anion catalyst, and a use of the dual-anion catalyst in catalytic degradation of a polyurethane material are provided. The preparation method includes: dissolving a metal salt in deionized water to produce a metal salt solution; adding a nitrogen-containing heterocyclic compound with hydroxyl or amino as a substrate to a reactor, adding the metal salt solution dropwise to the reactor, and conducting condensation reflux at 60° C. to 150° C. for 1 h to 8 h; adding an amine compound dropwise, and conducting a reaction; after the reaction is completed, conducting vacuum filtration to produce a filtrate; and subjecting the filtrate to evaporation, and oven-drying a resulting product to produce the dual-anion catalyst. A recovered polyol obtained through the degradation with the catalyst exhibits basically the same fundamental physical properties such as hydroxyl value, amine value, and viscosity to a virgin polyol.

The present invention discloses a bismuth tungstate-based heterojunction photocatalyst, a preparation method thereof and an application in organic wastewater treatment. The preparation method of the catalyst comprises the following steps: 1) preparing copper-ytterbium bimetallic doped carbon dots; 2) preparing carbon dot-modified cobalt disulfide; 3) preparing a bismuth tungstate complex doped with carbon dot-modified cobalt disulfide; 4) depositing silver on the surface of the bismuth tungstate complex doped with carbon dot-modified cobalt disulfide to obtain a bismuth tungstate-based heterojunction photocatalyst. The present invention provides a catalyst based on a multi-modified bismuth tungstate-based heterojunction, which can significantly improve its catalytic activity through a composite multi-effect modification treatment, and enables the catalyst to not only generate active oxygen under visible light, but also have the ability to efficiently generate active oxygen under ultrasonic excitation, which can greatly improve the ability of the catalyst to degrade organic dye pollutants in wastewater.

This invention provides a catalyst degradation diagnosis device and method that eliminates the need for floating-point calculations, enabling catalyst degradation diagnosis through simple calculations. The catalyst degradation diagnosis device includes: a catalyst disposed in the exhaust passage of an internal combustion engine; an upstream oxygen concentration detection unit disposed upstream of the catalyst; a downstream oxygen concentration detection unit disposed downstream of the catalyst; an upstream determination counting unit that counts the number of upstream determinations; and a downstream determination counting unit that counts the number of downstream determinations. When the number of upstream determinations in the upstream determination counting unit reaches a predetermined number, a catalyst degradation index value is calculated using the upstream and downstream determination counts. The counts in the upstream and downstream determination counting units are then reset. Catalyst degradation is diagnosed by comparing the catalyst degradation index value with a catalyst degradation index threshold.