234 results about "Nitrogen dioxide" patented technology

The invention belongs to the technical field of energy storage materials, and particularly relates to a high-entropy oxide Fe0. 2Co0. 2Ni0. 2Cu0. 2Zn0. 2O and an ultrafast synthesis method and application thereof. According to the preparation method, ferroferric oxide, cobalt oxide, nickel oxide, copper oxide and zinc oxide with equal molar ratio are adopted as direct synthesis raw materials, toxic gases such as chlorine and nitrogen dioxide generated in the synthesis process of a metal salt precursor are avoided, and the uniformly distributed single-phase high-entropy oxide is synthesized in an ultrafast manner within 10 seconds by using a Joule heating technology; the synthesized high-entropy oxide is used as a lithium ion battery negative electrode material, and shows more excellent electrochemical performance and cycling stability compared with other high-entropy oxides prepared from transition metals with different proportions; in the preparation process, extra additives are not needed, operation is easy, the synthesis speed is high, the yield is high, element distribution is uniform, and the method has the advantages of being low in cost, high in efficiency and free of pollution and has the industrialization prospect.

The invention relates to the technical field of environmental monitoring, and discloses a method for reconstructing carbon dioxide concentration enhancement based on multi-source satellite data, which comprises the following operation steps: collecting environmental information such as carbon dioxide dry air column concentration, nitrogen dioxide total column concentration, population density, land utilization, weather and the like to construct an environmental database; pre-processing the collected multi-source data to ensure time-space consistency; according to the population density of the region, the total column concentration of nitrogen dioxide and the land utilization type, setting a threshold value, and dividing the target region into a discharge region and a background region; constructing a background concentration reconstruction model, inverting the carbon dioxide background concentration, and calculating a residual error with actually measured carbon dioxide to obtain a carbon dioxide concentration enhanced sample; based on the carbon dioxide concentration enhanced sample, a concentration enhanced reconstruction model is constructed, and high-resolution carbon dioxide concentration enhanced spatial-temporal distribution is obtained. According to the method, high-frequency monitoring of the carbon source in the region can be realized spatially, and powerful support is provided for dynamic tracking of carbon emission.

The invention belongs to the field of engine aftertreatment systems, and provides a composite two-stage SCR system, a control method, an aftertreatment system.The system comprises a first SCR, a first ASC, a DOC, a DPF, a second SCR, a second ASC, a calculation control unit, an electric heating device, a gas concentration detection unit and an exhaust temperature unit; and the control unit is used for determining a urea injection control strategy of the first SCR and the second SCR and a working strategy of the electric heating device according to the nitrogen oxide concentration and the nitrogen dioxide proportion detected by the gas concentration detection unit and the temperature obtained by the exhaust temperature unit, and respectively controlling the first SCR, the second SCR and the electric heating device to work according to the determined strategies. According to the invention, the cooperative control requirement of ultralow nitrogen oxide emission and nitrous oxide gas emission limitation of the diesel engine can be met.

The invention discloses a SnO2 modified WO3 nanosheet composite gas-sensitive material as well as a preparation method and application thereof, and belongs to the technical field of inorganic composite materials. The preparation method comprises the following steps: dissolving WCl6 in ethanol, adding into a reaction kettle provided with a ceramic tube, carrying out hydrothermal reaction at 170-190 DEG C for 5-8 hours, taking out the ceramic tube, drying, and annealing to obtain a ceramic tube loaded with WO3 nanosheets; the preparation method comprises the following steps: dissolving SnO2, tin chloride and urea in water to obtain a mixed solution, adding the mixed solution into a reaction kettle filled with a ceramic tube loaded with a WO3 nanosheet, carrying out a hydrothermal reaction at 90-100 DEG C for 1-4 hours, taking out the ceramic tube after the reaction is finished, and drying to obtain the SnO2 modified WO3 nanosheet composite gas sensitive material, and enabling the SnO2 modified WO3 nanosheet to grow on the ceramic tube in situ. The preparation method is simple, the product is high in crystallinity and good in stability and is suitable for preparing a gas sensitive sensor material with high economical efficiency, and a sensor prepared from the SnO2 modified WO3 nanosheet composite gas sensitive material can effectively improve the gas sensitive performance of WO3 and shows an extremely high response value to nitrogen dioxide at a low temperature.

The invention discloses a method for removing nitrogen dioxide in dimethyl sulfoxide, and particularly relates to a method for removing nitrogen dioxide in a dimethyl sulfoxide crude product in the process of producing dimethyl sulfoxide from dimethyl sulfide, oxygen and nitrogen dioxide. A dimethyl sulfoxide crude product is introduced into the reactor, and the high-purity dimethyl sulfoxide can be separated and recovered from the crude product by circularly and repeatedly blowing off the dimethyl sulfoxide crude product in a closed device through nitrogen. The production method is suitable for a technology for producing dimethyl sulfoxide through nitrogen dioxide liquid phase oxidation, nitrogen dioxide in the crude product dimethyl sulfoxide is removed, the loss amount of nitrogen dioxide in the air stripping treatment process is greatly reduced, the operation process is easy and convenient to control, and the production method is suitable for modification and upgrading of an existing similar dimethyl sulfoxide production technology.

The invention discloses a coal bunker mixed gas concentration detection method based on a BSA algorithm and a BP neural network, and belongs to the technical field of gas detection. The coal bunker mixed gas concentration detection method based on the BSA algorithm and the BP neural network comprises the following steps: collecting gases including carbon monoxide, nitrogen dioxide, sulfur dioxide, hydrogen sulfide and methane, and constructing the BP neural network by taking normalized gas data as an input layer; and optimizing BP neural network parameters by using a BSA bird flock algorithm, carrying out network training by using a back propagation algorithm, and inputting gas concentration data collected in real time into the trained neural network in real time to obtain a predicted value of the gas concentration. According to the method, the parameters of the BP neural network are optimized through the BSA algorithm, the accuracy of network prediction is greatly improved, the gas concentration in the coal storage bunker can be monitored in real time, and once it is detected that the hazardous gas concentration exceeds the standard, quick response can be made and corresponding measures can be taken, so that potential safety risks are reduced.

The invention relates to the technical field of automobile air purification, and particularly discloses a filtering material, a preparation method of the filtering material and a novel automobile air conditioner multi-effect catalytic formaldehyde removal filter. The filtering material comprises a PET (Polyethylene Terephthalate) supporting layer, a gas filtering layer and a PP (Polypropylene) electrostatic filtering layer which are arranged in sequence, the gas filtering layer is prepared from the following raw materials in parts by weight: 30 to 90 parts of activated carbon and 10 to 70 parts of manganese catalyst. The gas filtering layer composed of the activated carbon and the manganese catalyst is matched with the filtering material composed of the PET supporting layer and the PP electrostatic filtering layer, four gases of n-butane, methylbenzene, sulfur dioxide and nitrogen dioxide can be adsorbed, the manganese catalyst degrades formaldehyde at normal temperature, meanwhile, the reaction on the formaldehyde is a catalytic reaction, and the environment-friendly effect is achieved. Therefore, the filter material disclosed by the invention also has longer service life, so that a filter made of the filter material has a better formaldehyde removal effect and longer service life.

The invention relates to the technical field of chemical synthesis, and discloses a method for preparing short-chain diacid by catalytic oxidation of polyethylene with an ionic liquid, which comprises the following steps: mixing the ionic liquid and polyethylene, and mixing for oxidation reaction in the presence of nitric oxide and oxygen to obtain the short-chain diacid. According to the method, the polyethylene is adopted as the raw material for the first time, the ionic liquid is used as the reaction catalyst and the reaction medium, nitric oxide is catalyzed to generate nitrogen dioxide, efficient catalytic oxidation of the polyethylene is achieved, the short-chain diacid product with the carbon number of 4-12 is obtained, the highest yield reaches 90% or above, and the influence on the yield is not large when the polyethylene recycled material is adopted. The method not only solves the problem of polyethylene waste recovery, but also solves the problem of high preparation cost of short-chain diacid, so that the preparation cost is greatly reduced.

The invention provides an ozone prediction method and device and electronic equipment, and the method comprises the steps: obtaining target prediction data, and obtaining prediction reference data, the target prediction data comprising target nitrogen dioxide data of a target region at a target prediction time; determining the concentration of nitrogen dioxide to be judged based on the target nitrogen dioxide data; determining target nitrogen dioxide concentration judgment data of the target area in the target prediction time from the prediction reference data; based on the to-be-judged nitrogen dioxide concentration and the target nitrogen dioxide concentration judgment data, determining target nitrogen dioxide concentration reference indication data, and based on the target nitrogen dioxide concentration reference indication data, determining a target ozone concentration standard exceeding prediction index of the target area at the target prediction time, the target ozone concentration standard exceeding prediction index support is used for indicating whether the ozone concentration of the target area in the target prediction time exceeds the standard or not. According to the embodiment of the invention, ozone prediction can be conveniently carried out so as to improve the ozone prediction rate.

The invention discloses a method for synthesizing an organic nitrile compound by using Pickering emulsion to electrocatalyze aldoxime dehydration, which comprises the following steps: ultrasonically dispersing carbon nanotubes in water, dissolving aldoxime organic matters in cyclohexane, mixing an aqueous solution with a cyclohexane solution, and forming the Pickering emulsion under the action of a homogenizer with the rotating speed of more than 1500rpm; then injecting a certain amount of nitrogen dioxide gas, continuously electrolyzing for 12 hours within the voltage range of-0.3 VRHE to-1.2 VRHE, and homogenizing for 5 seconds by the homogenizer every 5 minutes; the invention relates to the technical field of organic electro-synthesis, in particular to a method for synthesizing an organic nitrile compound by using Pickering emulsion to electrocatalyze aldoxime dehydration, which is a method for directly preparing organic nitrile from reactants aldoxime and nitrogen dioxide in a reactor under electric drive. According to the method, the traditional synthetic technical route of organic nitrile is avoided, the nitrile compound is synthesized in one step, and the method is a novel synthetic method which is brand-new, green, safe and low in harm to a human body and the environment.

A dimethyl sulfoxide synthesis system and a synthesis method, the system comprising: a fixed bed reactor (2) used to synthesize dimethyl sulfide, and an oxidation reactor (4) used to synthesize dimethyl sulfoxide. An external intensification unit (9) is disposed outside the oxidation reactor (4), the external intensification unit (9) comprising a first intensification reactor (901) and a second intensification reactor (902), the first intensification reactor (901) being disposed above the second intensification reactor (902), the first intensification reactor (901) being connected to a discharge port at a bottom end of the fixed bed reactor (2), the second intensification reactor (902) being connected to a nitrogen dioxide or oxygen storage tank (13), a connecting pipe (903) being disposed between the first intensification reactor (901) and the second intensification reactor (902), and a static mixer (904) being disposed in the connecting pipe (903).

The utility model belongs to the technical field of ethylene glycol preparation, and particularly relates to an esterification purge gas treatment device in a process of preparing ethylene glycol from synthesis gas, which comprises an MN recovery tower, a gas mixer, a tail gas heater, a tail gas reactor, a cooler and a tail gas absorption tower, tower top outlet gas of the MN recovery tower and purge gas from PSA desorption gas of a hydrogenation unit enter a gas mixer, are mixed in the gas mixer, then enter a tail gas heater to be heated and then enter a tail gas reactor to react, an outlet of the tail gas reactor is connected with an inlet of a cooler, an outlet of the cooler is connected with a tail gas absorption tower, and an outlet of the tail gas absorption tower is connected with an outlet of the MN recovery tower. The tail gas absorption tower is connected with a spray water inlet pipe and a waste gas discharge pipe; and the tail gas reactor is a fixed tubular reactor. According to the device, nitrogen oxide which cannot be directly discharged in esterification purge gas can react to generate harmless gas such as nitrogen and nitrogen dioxide, environmental pollution is avoided, the device can adapt to the shutdown working condition of an esterification system, air does not need to be supplemented to the MN recovery tower, and the technological operation risk is reduced.

The invention discloses a process and a device for recycling nitrogen dioxide, which are characterized in that degassed crude dimethyl sulfoxide is used as a raw material, nitrogen dioxide is absorbed by two stages of crude dimethyl sulfoxide and enters a micro-channel reactor to be used as a catalyst for oxidizing dimethyl sulfide, and recycling is realized. The device comprises a tail gas absorption unit, a microreactor unit, a heat exchanger unit and a separator unit, the technology adopts a dimethyl sulfoxide low-temperature absorption technology, and has the advantages of cyclic utilization of nitrogen oxides, energy conservation and emission reduction, convenience in operation, greenness, high efficiency and the like.

A method of reducing the emission of NOx, nitrogen oxide and / or nitrogen dioxide, from a diesel engine, comprising dosing a nitrogen containing detergent into diesel fuel. The nitrogen containing dete

The invention provides a built-in elastic connector for a cable accessory, and relates to the technical field of cable accessories. The fixing plate is of an annular plate structure. A first plug of a cylindrical structure is arranged on the inner side of the fixing plate in a sliding mode. A lower protection plate of a circular structure is fixedly arranged at the bottom of the outer side of one end of the first plug. An annular groove structure is formed in the inner side of the lower protection plate; the two sides of the bottom of the lower protection plate are each fixedly provided with a gas tank, and the gas tanks are filled with nitrogen dioxide gas. A second sliding rod of a rectangular rod structure is slidably arranged in a rectangular through groove in the inner side of the bottom of the lower protection plate. The top end of the second sliding rod is fixedly provided with a detection block of a wedge-shaped block structure, connection abnormity can be rapidly judged only through visual inspection, the timeliness and convenience of fault detection are greatly improved, the operation and maintenance cost and difficulty are reduced, the problem that connection looseness cannot be conveniently found in real time is solved, and the fault detection efficiency is improved. And the elastic force of the spring cannot be well monitored.

The invention belongs to the technical field of nano material application, and particularly relates to a nitrogen-rich carbon nitride gas-sensitive material, a gas-sensitive sensor and a preparation method and application of the nitrogen-rich carbon nitride gas-sensitive material and the gas-sensitive sensor. The ammonia leakage in the environment or the ammonia content in the expired gas of the human body can be accurately detected; and harmful gases such as ethanol, methanol, isopropanol, triethylamine, acetone, trimethylamine, nitrogen dioxide and the like can be detected. The nitrogen-rich carbon nitride gas-sensitive material is prepared into a gas-sensitive sensor, and the gas-sensitive sensor has the advantages of high ammonia responsivity, good selectivity, good stability, strong anti-interference performance and the like at room temperature. The gas sensor does not need to be heated during use, a conventional gas sensor heating step is omitted, and the gas sensor can be directly placed in a normal-temperature environment for operation; and different substrate materials can be used for constructing rigid and flexible substrate sensors, and the application method is simple, easy to operate, good in effect and wide in application prospect.

The utility model discloses a diesel generator flue gas purification mechanism for civil air defence engineering, including air inlet pipe and purification bin, the air inlet pipe one end is linked with diesel generator exhaust pipe in civil air defence engineering power generation room intercommunication, the other end of air inlet pipe is inserted into the purification bin and the opening direction is perpendicular to downward, the open end position of air inlet pipe in the purification bin is connected with the shunt joint, each interface of shunt joint all is connected with the jet pipe that the air hole of pipe body lateral wall is evenly set up, the utility model relates to civil air defence engineering technical field, utilize liquid supply booster pump and press into the spray subassembly in alkaline solution (15% magnesium hydroxide compound agent), and further via spray subassembly to the spray of filler layer, make the nitrogen monoxide, nitrogen dioxide, sulfur dioxide and particulate matter etc. in tail gas contact with the alkaline water mist in purification bin and filler layer, to the purification treatment of nitrogen monoxide, nitrogen dioxide, sulfur dioxide and particulate matter.

The invention belongs to the technical field of medicine synthesis, and discloses a preparation method of a sodium nitroprusside raw material medicine. According to the method, weak acid is adopted for catalysis, the effect of remarkably reducing generation of toxic substances such as cyanide and nitrogen dioxide is achieved by controlling the material dripping speed and the dripping pH, the reaction is mild, the technological operation is safe and controllable, and industrial production of the sodium nitroprusside raw material medicine is facilitated. According to the preparation method of some examples, silica gel filtration is used for post-treatment, the residual risk of impurities such as sodium ferricyanide, ferric ferrocyanide and ferric ferricyanide is reduced, and the purity of the raw material medicine is larger than or equal to 99.9% and is far superior to the requirements of pharmacopoeia of various countries.

The invention relates to a method for producing an electrochemical cell, preferably a fuel cell, in particular a PEM fuel cell, in which a catalyst material is deposited on a carbon-based support material having a porous structure in order to form an electrode of a membrane-electrode assembly and the carbon-based support material is subsequently subjected to a thermal post-treatment, the carbon-based support material is selectively oxidized by means of a reaction gas containing at least one reactant, preferably carbon dioxide (CO2), ammonia (NH3), nitrogen dioxide (NO2), nitrogen monoxide (NO) and / or water vapor (H2O). The invention also relates to an electrochemical cell, preferably a fuel cell, in particular a PEM fuel cell.

The invention belongs to the technical field of nano sensing and gas monitoring, and discloses an MXene / ZnO nano composite material as well as a preparation method and application thereof. The preparation method comprises the following steps: firstly, etching Ti3AlC2 by using hydrochloric acid and lithium fluoride to obtain multi-layer two-dimensional MXene, and then carrying out ultrasonic stripping and freeze drying to obtain few-layer MXene; carrying out alkalization treatment on few layers of MXene, and then carrying out centrifugal cleaning to obtain 1D / 2D-MXene with a composite structure; the preparation method comprises the following steps: adding 1D / 2D-MXene and zinc acetate dihydrate into a mixed solution of water and ethanol, and carrying out a hydrothermal reaction; the preparation method comprises the following steps of: performing centrifugal cleaning and vacuum drying to obtain a multi-level 1D / 2D-MXene / 0D-ZnO nano-composite structure consisting of 0D-ZnO, 1D-MXene and 2D-MXene, and the multi-dimensional nano-composite structure is suitable for preparing a gas sensor and is used for detecting low-concentration nitrogen dioxide gas at room temperature. The nano composite material and the sensor prepared by the invention show excellent gas-sensitive performance on nitrogen dioxide gas, are high in sensitivity, can realize normal-temperature detection, and have relatively great application potential.

An engine data processor for an internal combustion engine is structured and arranged for: receiving a geometric characteristic of an exhaust unit through which the exhaust gas composition can be discharged, and determining from the geometric characteristic a smoke visibility limit value; receiving filter fill status information from an exhaust gas filter for filtering the exhaust gas composition; receiving a mean catalytic converter temperature of an exhaust gas catalytic converter for catalyzing the exhaust gas composition and determining a nitrogen dioxide conversion rate subject to the filter fill status information which has been received and the mean catalytic converter temperature; comparing the calculated nitrogen dioxide conversion rate with the smoke visibility limit value, and determining therefrom a control variable for the internal combustion engine so that the exhaust gas composition is invisible; and issuing the control variable.

The invention provides a safety protection method, device and equipment in a cockpit and a readable storage medium, the method comprises the following steps: receiving various index information monitored by a sensor, the various index information comprising concentrations of a plurality of gases in formaldehyde, nitrogen dioxide, oxygen and carbon monoxide; corresponding safety protection measures are matched and executed according to the standard reaching conditions of the various index information, the flameout state of the vehicle and the biological conditions in the vehicle, and the biological conditions comprise the character conditions and the animal conditions. According to the method, the effects of accurately detecting the safety in the vehicle and carrying out the safety protection process in time can be achieved.

The invention relates to a novel ecological new energy highway. Relates to the fields of new energy application, ecological restoration, haze treatment, climate and temperature regulation, ecological civilization construction, ecological city and Chinese modernization. The novel ecological new energy highway can effectively solve the problems of pavement high temperature and air quality, plays an important role in adjusting temperature and climate, and can effectively purify automobile exhaust such as harmful gases such as carbon dioxide, sulfur dioxide and nitrogen dioxide. Compared with a traditional road, the road has the advantages of new energy productivity and ecological restoration, and has a wide application prospect.

The application discloses a kind of based on plant extract liquid atomization and bionic controller's waste gas purification device, it is related to waste gas purification treatment field, including plant extract liquid emitter, UV photocatalytic lamp assembly, ultrasonic generator, low-temperature plasma filter device and bionic flow control device;With plant extract liquid specific component combination UV photoelectrolytic catalytic technology, oxidation decomposition nitrogen oxide generated free radical, block free radical chain reaction to remove nitrogen dioxide, provide more depth efficient purification effect, by ultrasonic atomization technology plant extract liquid is converted into small ionic state particles, combination low-temperature plasma filter device reduces waste gas diffusion rate, greatly increase plant extract liquid and impurity and harmful tail gas contact area and reaction length, by bionic flow control device, utilize the uneven deformation characteristics caused by different thermal expansion coefficients of bimetallic strip, control switch and adjust flow size, further improve resource utilization efficiency and sustainability.

Flue gas pollutants are particulate matter, gaseous pollutants, and other harmful substances generated during the combustion of fossil fuels (such as coal, oil, natural gas). These pollutants include PM2.5, PM10, sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), and volatile organic compounds (VOCs), which pose serious hazards to the environment and human health. The present invention proposes a method for predicting the generation amount of flue gas pollutants, which is predicted by the constructed T3N model and smooth loss function. This method can accurately master the data of flue gas generation amount, thereby realizing the real-time regulation and optimization operation of pollutant sources, and providing more effective means for environmental protection and pollution control.

The invention relates to an austenitic stainless steel food-grade pipe welding spot cleaning passivator. The austenitic stainless steel food-grade pipe welding spot cleaning passivator comprises the following components in parts by mass: 0.2-1.2 parts of a complexing agent, 0.5-2.5 parts of a sealing agent, 9.5-18 parts of organic acid, 1-5 parts of an oxidizing agent, 1-5 parts of a coordination agent, 0.2-2 parts of a corrosion inhibitor, 0.4-1.5 parts of an active agent and 64.8-87.2 parts of water. Through compounding of the whole materials, after a stainless steel workpiece is cleaned and passivated, no heavy metal is left on the surface of the workpiece, the corrosion resistance of the surface of the workpiece can be improved, the service life of the workpiece is prolonged, harmful gas, acid mist and toxic substances are not generated in the process of cleaning and passivating the workpiece, and the service life of the workpiece is prolonged. The austenitic stainless steel cleaning and passivating agent is safe and environment-friendly to use, and solves the problems that in the process of cleaning and passivating austenitic stainless steel products by adopting a pickling and passivating method in the market, acid mist is formed, nitrogen dioxide polluting the atmosphere is generated, chromium compounds with high toxicity are generated, and the health of operators is harmed and the environment is polluted.

An internal combustion engine system is described herein. The system uses a NOx detector at the exhaust of an internal combustion engine to compensate for the effects of NO2 on the measurements of NOx detectors at other locations, such as the input and the output of an SCR system. A controller uses the difference in measured NOx volume fractions between the NOx detector at the exhaust and other NOx detectors to modify the operation of the combustion engine system as well as, in some examples, determine NO2 created by a device containing a precious metal catalyst, such as precious metal containing diesel particular filter (DPF) and / or a diesel oxidizing catalyst (DOC), that oxidizes a portion of the exhaust from NO to NO2.

The invention discloses a method for relieving and eliminating sewage anaerobic fermentation stink. The method comprises the following steps: mixing malodorous gas generated by anaerobic fermentation with nitrogen dioxide, and carrying out gas-phase oxidation reaction; the reacted gas is subjected to ultraviolet photolysis treatment, so that nitrogen dioxide is decomposed to generate ozone; and the generated ozone is utilized to continuously oxidize the malodorous substances. The method can also comprise a source sulfur fixation step: adding a sulfur fixation agent into the anaerobic fermentation system, and reducing the generation of hydrogen sulfide from the source. Nitrogen dioxide can be prepared from steel cylinder gas, industrial waste gas or on site, and the on-site preparation comprises an ammonia water / ammonium salt catalytic oxidation method and a nitric acid reduction method. Through multi-stage cooperation of'source sulfur fixation + NO2 gas-phase oxidation + UV ozone conversion + ozone continuous oxidation ', efficient removal of malodorous gas is achieved, an ozone generator does not need to be additionally arranged, nitrogen dioxide residues are thoroughly eliminated, secondary pollution is avoided, equipment is compact, and the operation cost is low.

A method of reducing the emission of nitrogen oxide and / or nitrogen dioxide from a diesel engine combusting a diesel fuel composition, the method comprising dosing into the diesel fuel composition as an additive at least one ester compound; wherein the ester compound is the reaction product of: a) an optionally substituted polycarboxylic acid or an anhydride thereof; and b) an alcohol of formula H-(OR)n-OR1, wherein R is an optionally substituted alkylene group, R1 is hydrogen or an optionally substituted hydrocarbyl group and n is 0 or a positive integer; provided that n is not 0 when R1 is hydrogen.

The invention discloses a nano spherical SnPd oxide, which is prepared by the following steps: firstly, cross-linking tannic acid and formaldehyde at room temperature by taking F127 as a surfactant, then adding stannous sulfate and palladium nitrate dihydrate for chelation, carrying out hydrothermal reaction to obtain a SnPd phenolic hybrid, and finally, calcining to obtain the nano spherical SnPd oxide, namely SP for short. SP is an n-type semiconductor, and the chemical composition of SP is SnO2 and Pd; the diameter of the mesoporous nanosphere is 100-150nm, and the average pore size of the mesoporous nanosphere is 5-7nm. The preparation method comprises the following steps: 1, preparing the SnPd phenolic hybrid SPZ; 2, preparation of an SnPd oxide SP; according to the SP-based hydrogen sensor and the preparation method thereof, the response value is 14.6, the response time is 1.5-2 seconds, the recovery time is 7-10 seconds, and the minimum hydrogen concentration detection is 0.2 ppm; the cycling stability reaches 30 days; the catalyst has selectivity on ammonia gas, methane, carbon dioxide, carbon monoxide and nitrogen dioxide.