9 results about "Kinetic diameter" patented technology

The invention discloses a hierarchical porous Ti-MOR molecular sieve as well as a preparation method and application thereof, and belongs to the technical field of molecular sieves. The preparation method comprises the following steps: at room temperature, mixing a silicon source, an aluminum source, an alkali source, a seed crystal, a pore-enlarging agent and water to obtain a gel precursor for synthesizing the molecular sieve, carrying out hydrothermal crystallization and alkali treatment to obtain a hierarchical pore structure MOR molecular sieve with mesopores and macropores, carrying out acid pickling, and carrying out gas-solid phase same crystal substitution on the molecular sieve and titanium tetrachloride to finally prepare the hierarchical pore Ti-MOR molecular sieve. According to the hierarchical porous Ti-MOR molecular sieve disclosed by the invention, reactant molecules with relatively large dynamic diameters can effectively enter and exit zeolite pore channels, and the hierarchical porous Ti-MOR molecular sieve shows excellent catalytic performance in a cyclohexanone oximation reaction.

This invention relates to a method for determining the upper limit of adsorbate gas molecule aggregation in porous materials using a liquid-driven gas displacement method. Belonging to the field of materials characterization technology, it addresses at least one of the problems of existing technologies being unable to directly and effectively determine the pore size range in which adsorbate gas condenses within porous materials with complex pore size distributions at room temperature and pressure. The method of this invention is based on the liquid-driven gas displacement method. It uses liquid probe molecules with different molecular dynamic diameters to displace aggregated adsorbate gas molecules from the micropores of the porous material. The resulting displacement amounts are then compared, directly correlating the dynamic diameter of the liquid probe molecules with the upper limit of adsorbate gas molecule aggregation. By determining the aggregation upper limits of various adsorbate gas molecules in porous materials, the adjustment of the micropore structure of porous materials can be more targeted, thereby effectively improving their adsorption and separation performance.

The invention relates to an adsorption material, in particular to a microporous Ni-MOF adsorption material and a preparation method and application thereof. The microporous Ni-MOF material provided by the invention has remarkable advantages in structural stability and aperture matching, and is just matched with the kinetic diameters of hexane isomers and benzene / cyclohexane molecules, so that the microporous Ni-MOF material can realize an efficient molecular sieving effect. Especially, the selective recognition of straight-chain / single-branched-chain and double-branched-chain hexane realizes the'complete cutting 'capability which cannot be achieved by the existing adsorbent.

The application discloses a zeolite-like imidazole framework material and a preparation method and application thereof, and comprises the following steps: adding benzimidazole, 4-nitroimidazole and a zinc source into an amide solvent to mix, to obtain a mixed solution; after heating and reacting the mixed solution, cooling, washing and drying, the zeolite-like imidazole framework material is obtained. In the reaction process of benzimidazole and the zinc source, 4-nitroimidazole is added, the benzimidazole in the original structure of ZIF-7 is replaced by 4-nitroimidazole, a polar group (-NO2) is introduced, the NO2-ZIF-7-0.4 zeolite-like imidazole framework material is obtained, the pore size is concentratedly distributed in the vicinity, is highly matched with the kinetic diameter of Rn atoms, the original narrow window of the ZIF-7 material is widened, the limitation of the window on the diffusion of Rn atoms in the adsorption material is avoided, the limited effect and the polarization effect are synergistically effective, and the adsorption performance of the modified ZIF-7 material on Rn is increased.

The application discloses application of carbon molecular sieve in separation and purification of gaseous fluorides. The carbon molecular sieve material with the most probable pore diameter is used as an adsorbent, hydrogen fluoride is adsorbed and removed from gaseous fluorides based on the size screening principle, and other gaseous fluorides with larger kinetic diameters are almost completely rejected, so that the screening and removal effect of hydrogen fluoride impurities in various gaseous fluorides is realized. Compared with traditional alkali metal fluoride adsorption materials such as NaF and KF, the carbon molecular sieve material has the advantages of stable structure, low cost, corrosion resistance, small adsorption heat and the like, and is an adsorption and separation material with excellent industrial application prospect for separating hydrogen fluoride impurities from various gaseous fluorides.

The present application belongs to the field of molecular sieve membrane repair, and particularly relates to a method for repairing a molecular sieve membrane. The method uses NO2 and SO2 to repair the molecular sieve membrane. NO2 molecules are prone to dimerization to form N2O4 under certain conditions (low temperature or high pressure), and N2O4 can react with SO2 to form a complex ONONO-SO3, which can form strong affinity with the hydroxyl group exposed at the defect site of the molecular sieve membrane, thereby plugging the molecular sieve membrane channel and repairing the molecular sieve membrane. For small-pore molecular sieve membranes such as six-membered ring or eight-membered ring, N2O4 has a kinetic diameter greater than the pore diameter of the molecular sieve membrane, so it cannot enter the molecular sieve membrane channel and cause channel plugging. For ten-membered ring or twelve-membered ring molecular sieve membranes with larger pore diameters, the adsorption of the ONONO-SO3 complex is not strong due to the larger pore diameter of the molecular sieve membrane, and selective heating desorption can be selected, so the channel will not be permanently plugged.

The invention discloses an application of a carbon molecular sieve in gas fluoride separation and purification. According to the invention, the carbon molecular sieve material with the most probable aperture of # imgabs0 # is used as an adsorbent, hydrogen fluoride is adsorbed and removed from gas fluoride based on a size screening principle, and other gas fluoride with larger dynamic diameter is almost completely repelled, so that the effect of screening and removing hydrogen fluoride impurities in various gas fluorides is realized. Compared with NaF, KF and other traditional alkali metal fluoride adsorption materials, the material also has the advantages of stable structure, low cost, corrosion resistance, small adsorption heat and the like, and is an adsorption separation material for separating hydrogen fluoride impurities and various gas fluorides with excellent industrial application prospects.

The application provides an electrode structure for in-situ nitrogen separation, a fuel cell and a preparation method, and belongs to the technical field of fuel cells. The electrode structure comprises an anode gas diffusion layer and an anode catalytic layer, and a nitrogen selective separation adsorption layer is arranged between the anode gas diffusion layer and the anode catalytic layer. The separation adsorption layer is a porous film layer with a pore size between the kinetic diameter of a hydrogen molecule and the kinetic diameter of a nitrogen molecule, and is deposited on the side surface of the anode gas diffusion layer facing the anode catalytic layer in an in-situ growth manner. By adopting the technical scheme provided in the embodiment of the application, the problems in the prior art that the system volume increases sharply, the in-situ nitrogen separation cannot be realized at the electrode level, the nitrogen occupies the active sites of the catalytic layer, hinders the diffusion of hydrogen and accelerates the performance decay of the electrode can be solved.

The present invention provides an application of a metal-organic framework material JNU-2 in separating chemical benzene compounds and / or hexane isomers. The application adopts a penetration test for separation, comprising the following steps: (1) first activating the metal-organic framework material JNU-2; (2) filling 0.7-1.2 g of the metal-organic framework material JNU-2 powder into a stainless steel column filled with silica glass wool, and performing an ionization reaction at a temperature of 353 K and a carrier gas of helium at a flow rate of 3.0-20 mL min ‑1 Penetration experiments with gaseous mixtures of two or more chemical benzene compounds or hexane isomers were conducted. The material's interconnected channels and pores, along with a window aperture of approximately #imgabs0#, are larger than the kinetic diameters of #imgabs1# and #imgabs2# but comparable to #imgabs3#. This prevents oX molecules from diffusing into the internal cavity of JNU‑2, as is the case with other BTEX molecules. Furthermore, this value is within the molecular size range of hexane isomers, effectively excluding the slightly larger 22DMB molecule.