61 results about "Lewis acids and bases" patented technology

The invention belongs to the field of nano materials, and relates to an MgAl LDO / nitrogen vacancy carbon nitride-based photocatalyst as well as a preparation method and application thereof. According to the preparation method, a carbon nitride (g-C3N4) nanosheet rich in nitrogen vacancies is prepared, magnesium-aluminum bimetallic layered hydroxide (MgAl LDH) is deposited on the surface of the carbon nitride (g-C3N4) nanosheet in situ, and the magnesium-aluminum bimetallic layered oxide (MgAl LDH) / nitrogen vacancy carbon nitride composite photocatalytic CO2 reduction material which is low in cost, easy to obtain, stable in structure and high in catalytic activity is prepared through continuous calcination. The surface of MgAlLDO has abundant Lewis base / acid sites, O<2->, Mg<2+>-O<2-> and OH groups are used as Lewis base sites to improve the adsorption activation capacity of CO2, Al<3+> and Al<3+>-O<2-> are used as Lewis acid sites to improve the adsorption / dissociation of H2O, the oxidation semi-reaction of H2O is accelerated, more protons are provided, and the CO2 reduction activity is further improved. Meanwhile, surface nitrogen vacancies are beneficial to separation of photo-induced electrons and holes, and the Lewis acid / alkali and the nitrogen vacancies cooperate to enable the composite photocatalytic material to have excellent CO2 photocatalytic performance.

The invention discloses an efficient and energy-saving method for trapping carbon by ionic liquid, which is applied to chemical trapping of carbon dioxide. A high-capacity, low-energy consumption and recyclable trapping of carbon dioxide is realized by using a synergistic effect of Lewis acids and bases and C-H...O, and thus a potential method is provided for industrial trapping of carbon dioxide. Compared with a conventional method, the method adopted by the invention is very novel, and has the following characteristics and beneficial effects: 1, through designing anion functionalized ionic liquid with different space structures and using the synergistic effect of Lewis acids and bases and C-H...O between carbonyl and carbon dioxide, the trapping amount of the ionic liquid to the carbon dioxide is greatly increased, which is up to 1.4mol / mole ionic liquid; and 2, due to the introduction of an electron-withdrawing function of the carbonyl, the acting enthalpy of the ionic liquid and the carbon dioxide is reduced, and the carbon dioxide is more easily desorbed.

The invention provides a synthetic method for catalyzing beta-amino alcohol, alpha, beta-unsaturated ketone and beta-aminoketone based on a frustrated Lewis acid-base pair. A novel frustrated Lewis acid-base pair I which is stable in air is adopted as a catalyst and has the structural formula of PhN(CH2C6H4)2SbF, wherein Sb atom is bonded with two carbon atoms in a ligand and also forms a coordination bond together with nitrogen atom in the ligand. The method provides an efficient and environmental-friendly way for preparing a beta-amino alcohol compound from an epoxy compound and amine, preparing an alpha, beta-unsaturated ketone compound from aldehyde and ketone and preparing beta-aminoketone from aldehyde, ketone and amine. The frustrated Lewis acid-base pair is good in catalytic performance and can be repeatedly used, both the selectivity and the productivity of target products are close to 100%, the reaction conditions are simple, the operation is easy, the cost is low and the preparation process is environmental friendly.

The invention discloses a special catalyst for preparing isophthalonitrile by ammoxidation of m-xylene. The carrier is silica gel, the main catalyst is three components of V, Mo and Sb, and the co-catalyst is at least one of D and E components. species; its active components are expressed as: VMo b Sb c D. d E. e o x ; The D is boron, chromium, titanium, phosphorus, nickel, bismuth, manganese, iron, cobalt, copper, zinc or tin; E is potassium, lithium, sodium, cesium, magnesium or calcium. The invention also discloses the preparation method and application of the catalyst. In the present invention, groups containing lone electron pairs on silicon are used to carry out Lewis acid-base reaction with inorganic elements, thereby strengthening the effect of inorganic oxides and supports; at the same time, the dispersion of inorganic oxides is more uniform, the loss of catalyst components is small, and the catalytic activity is high. , good selectivity, prolonging the service life of industrial catalysts from one year to more than two years. The preparation method of the catalyst is simple, the thermal stability and mechanical strength are good, and the catalyst can be used in fixed-bed and fluidized-bed reactors.

The invention provides a preparation method of a nanofiltration membrane based on polyamidoxime as a boundary layer, and belongs to the field of nanofiltration membrane preparation. According to the invention, the polyamidoxime rich in amidoxime groups is used as an organic boundary layer, so that the hydrophilicity of the surface of a supporting layer can be obviously enhanced, the uniform spreading of a water solution of a water-phase monomer piperazine on the boundary layer is facilitated, a compact and thin PA layer with small surface aperture is prepared, and the polyamidoxime can generate hydrogen-bond interaction and Lewis acid-base interaction with piperazine, the diffusion of piperazine to an oil phase solution is effectively inhibited, the instability of interfacial polymerization is caused, a wrinkled PA layer with relatively strong electronegativity on the surface is formed, the effective permeation area is further remarkably increased, the permeation transmission channels of the finally obtained nanofiltration membrane are increased and the transmission resistance is reduced due to the reduction of the thickness of the PA layer and the increase of the effective permeation area of the PA layer, and the permeation flus is greatly improved. Meanwhile, the surface of the PA layer has relatively strong electronegativity and relatively small surface aperture, so that the solute rejection rate is increased.

The present disclosure provides a Lewis acid-base pair catalytic initiator and an application thereof. The Lewis acid-base pair catalytic initiator includes a Lewis acid and a Lewis base, the Lewis acid having a structural general formula as shown in formula (I) and the Lewis base having a structural general formula as shown in formula (II); wherein: the A is selected from element Baron or element Aluminum; the R1, R2, R3, R4 are independently selected from alkyl, alkoxy, aryl or halogen groups; the alkyl or alkoxy have a carbon number being equal to or greater than 1 to equal to or less than 16; the aryl contains substituents with the number being equal to or less than 5, the substituents being selected from methyl, methoxy or halogen; n is selected from an integer from 1 to 16.

The invention provides amphiphilic block polymer nanoparticles with different morphologies, a preparation method and application thereof, and relates to the technical field of polymers. In the present invention, under the catalysis of Lewis acid-base pair, the acrylate monomer stabilizes the segment monomer and the nucleation segment monomer is polymerized to obtain amphiphilic block polymer nanoparticles with different morphologies; Nucleating segment monomers include trifluoroethyl methacrylate or benzyl methacrylate. The Lewis acid-base pair used in the invention can efficiently synthesize highly asymmetric amphiphilic block polymer nanoparticles with different morphologies through a "one-pot, one-step" method as a catalyst, and the polymer nanoparticles have a clear structure, and the monomers Less mis-insertion, good polymerization control and narrow molecular weight distribution. Amphiphilic block polymer nanoparticles with spherical, worm and vesicle morphologies can be obtained by controlling the dosage ratio of the two monomers.

The invention relates to a method for promoting the ionization of benzoic acid derivatives based on Ag NPs. The adopted technical scheme is: dissolving benzoic acid derivatives in absolute ethanol, then adding Ag NPs catalyst, and ionizing reaction under light. In the present invention, there is no conventional addition of alkali in this system, but it can be clearly seen that the degree of ionization is gradually increasing, so the "racemate of Lewis acid-base"-Ag NPs fully exerts the role of alkali, and the more critical It is that it acts as a boost far beyond that of the base base. Moreover, the present invention introduces surface-enhanced Raman spectroscopy technology, and monitors the system through this simple and efficient means. Moreover, the present invention clarifies the flow direction of electrons. More importantly, the present invention regulates the generation of hot electrons based on the electron-withdrawing effect, prompting the system to generate more hot electrons, and realizing reactions that cannot occur in conventional organic chemistry.