30results about How to "Many catalytic active sites" patented technology

The invention provides a catalyst for electrochemical reduction of carbon dioxide. The catalyst is characterized by comprising coralline-shaped nanometer stannous oxide. The preparation method of the coralline-shaped nanometer stannous oxide comprises the following steps of dissolving urea and stannous chloride in deionized water to obtain a catalyst precursor; placing the catalyst precursor in a reaction kettle; carrying out hydrothermal reaction and centrifugal separation; washing and centrifugally separating the obtained solid; and drying the solid to obtain the coralline-shaped nanometer stannous oxide. The stannous oxide catalyst provided by the invention is presented with a particular root-shaped coral stacked morphology, is provided with vivid crystal surfaces (101) and (102), and is compatible with high electrocatalytic activity and selectivity on reduction of the carbon oxide, and the utilization energy efficiency of the carbon oxide can be particularly and remarkably improved. Further, the preparation method of the catalyst, provided by the invention, has the advantages of simplicity in operation, greenness, high yield and wide application prospect.

The present invention relates to a polyformaldehyde dimethyl ether preparation method, wherein the problem that the catalyst has corrosion in the prior art is mainly solved with the present invention. The technical scheme comprises that: methanol or dimethyl ether, and formaldehyde or trioxymethylene are adopted as raw materials, a molar ratio of the methanol or the dimethyl ether to the formaldehyde or the trioxymethylene is 1:0.1-10, and the reaction raw materials contact a catalyst at a reaction temperature of 50-200 DEG C under a reaction pressure of 0.1-10 MPa to produce polyformaldehyde dimethyl ether, wherein the catalyst is at least the one selected from a binder-free ZSM-5 molecular sieve and a binder-free ZSM-11 molecular sieve. With the technical scheme, the problem in the prior is well solved, and the method can be used for industrial production of polyformaldehyde dimethyl ether.

The invention belongs to the technical field of material chemistry, and particularly relates to a macro preparation method for a carbon doped zinc oxide-based visible-light catalyst. The method disclosed by the invention adopts a micro-molecular organic matter combustion-supporting method for macroscopically preparing the carbon commingled zinc oxide-based visible-light catalyst. The preparation principle of the catalyst is that the reaction heat of the combustion of the micro-molecular organic matter at a high temperature is used to realize effective sedimentation and doping of a carbon element in zinc oxide crystals; at the same time, a large number of gases are generated in reaction processes, products can be crushed effectively, so that small-sized carbon doped zinc oxide-based nano particles are obtained, and the macro preparation of the carbon doped zinc oxide-based visible-light catalyst is realized. Prepared nano-powder has the advantages that the dispersibility is good, the particle sizes are small, the sizes are uniform, the visible-light catalytic property is excellent, and the chemical stability is high; at the room temperature of 27 DEG C-33 DEG C and sunlight exposures, the visible-light catalyst can completely degrade an organic dyestuff rhodamine B in 15 minutes, so that the catalyst can be applied to the fields of controlling environmental pollutants and the like.