Beijing University of Chemical Tehcnology

Jiangyin Ruifa Chemical Co., Ltd.

Dianqing Li

Xue Fei Duan

Junting Feng

Yanjun Lin

Yufei He

Feng Li

Hui Zhang

Rui Ma

Peng Chen

Yanan Liu

Chao Gao

Jiali Chen

Fazhi Zhang

Yongjun Feng

Rong Hou

Xiaoyan Ma

Zhi Lv

Xiangyu Xu

Fengzhi Fu

Kaitao Li

Bo Ning

Chenfa Wen

Xuchang Tan

Cu/MMgOinterfacial catalyst for selective alkyne hydrogenation and its preparation method are disclosed. The preparation method of the catalyst includes: the mixture of salt and alkali solution is nucleated momentarily by nucleation/crystallization isolation method, preparing the composite metal hydroxide CuMMg-LDHs as precursor, which has typical hexagonal morphology of the double hydroxide; the precursor is topologically transformed by heat treatment to produce unsaturated oxide; the catalyst with Cu-MMgOinterface structure is prepared by separating and electronically modifying Cu particles. By adjusting the ratio of Cu/Min LDHs, the electronic and geometric structure of Cu-MMgOinterface can be flexibly controlled, thus enhancing the reaction activity, product selectivity and stability. The catalyst can be used in the selective hydrogenation of various alkynes in the fields of petrochemical and fine chemical industry, with the outstanding catalytic activity and C&#x2550;C double bond selectivity. The catalyst also has good reusability.

Cu/MMgOinterfacial catalyst for selective alkyne hydrogenation and its preparation method

The purpose of the invention is to provide a supported bimetallic core-shell structure catalyst and its preparation method. Supporter, metal salt and reducing agent solution are mixed to synthesize the catalyst M@PdM/ZT by using a one-step synthesis method, wherein the active metal particle M@PdM as core-shell structure, M Is the core representing one of the Ag, Pt, Au and Ir. ZT is the supporter, representing one of hydrotalcite (MgAl-LDH), alumina (AlO) and silica (SiO). By changing the temperature and the reaction time to control the kinetic behavior of the reduction of two kinds of metal ions to realize the construction of core-shell structure. Active metal particle composition and shell thickness are regulated by controlling metal ion concentration. The bimetallic core-shell catalyst prepared by this method showed excellent selectivity and stability in acetylene selective hydrogenation and anthraquinone hydrogenation.

Supported bimetallic core-shell structure catalyst and its preparation method

The present invention belongs to the synthesis technology field of inorganic functional materials, and particularly provides a self-balanced high-pressure and high-shear autoclave and its application in the preparation of layered double hydroxides (LDHs). In this invention, by imbedding the handpiece of emulsification mill into the autoclave, and by taking the motor driving system outside of the autoclave, the pressure of the autoclave can be highly stable by the use of self-balanced seal gland. These characters solve the problem that the typical emulsification mill cannot be used in high-pressure system, and ensure the crystallization under the high-pressure and high-shear conditions. Such autoclave takes the advantages of additional equipment, and eliminates the volume effect in the amplification process. By the use of this new autoclave, the reaction time can be shorten from 24 hours to 2-6 hours, the reaction temperature can be reduced from 180&#xb0; C. to 140&#xb0; C. The LDHs products with small particle size and narrow size distribution are obtained. These results are better than those prepared at the laboratory level.

Self-balanced high-pressure and high-shear autoclave and the application in the preparation of layered double hydroxides

A process for preparing a catalyst comprising palladium supported on a carrier via a layered precursor, comprising the following steps: (1) synthesis of hydrotalcite layered precursor which comprises promoting metal element and aluminium on the surface of the carrier of A1Omicrospheres, the atoms of the promoting metal and aluminium being highly dispersed by each other and bonded firmly to the carrier due to the crystal lattice positioning effect of the hydrotalcite crystal; (2) introduction of palladium into the carrier through impregnation; (3) drying; and (4) calcination and reduction with H, the hydrotalcite layered precursor being converted into a composite oxide which consists of oxides of the promoting metal and aluminium, and the promoting metal element and aluminium being highly dispersed by each other and being able to separate and disperse the mainly active palladium element loaded later. The process has the advantages of improving the catalytic performance of the catalyst, enhancing the stability of the catalyst, and achieving the object of reducing the consumption of the precious metal-palladium.

Process for preparing catalyst comprising palladium supported on carrier with high dispersion

A process for preparing supported noble metal catalyst in situ is provided by mixing and crystallizing hexamethylenetetramine, soluble divalent metal salts solution, Al2O3 carriers and soluble noble metal salts solution wherein the hexamethylenetetramine is used as a precipitating agent for preparing hydrotalcite and a reducing agent of noble metal precursor. During the growth process of hydrotalcite, Al3+ on the Al2O3 carrier's surface is directly used as the trivalent metal ions in the laminate structure and the hydrotalcite is obtained on the surface of the Al2O3 carriers by in-situ growth. A supported catalyst Me-LDHs-Al2O3 containing an elementary noble metal is produced wherein the noble metal element particle in the catalyst has a particle size of 10 to 60 nm, and is evenly and stably dispersed on or between slabs of the hydrotalcite.

Supported noble metal catalyst and process for preparing the same in situ

Disclosed is a clean method for preparing layered double hydroxides (LDHs), in which hydroxides of different metals are used as starting materials for production of LDHs by atom-economical reactions. The atom efficiency of the reaction is 100% in each case because all the atoms of the reactants are converted into the target product since only M(OH), M(OH), and COor HAare used, without any NaOH or other materials. Since there is no by-product, filtration or washing process is unnecessary. The consequent reduction in water consumption is also beneficial to the environment.

Clean method for preparing layered double hydroxides

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Beijing, China

Dianqing Li