Provided are a supported catalyst, a preparation method therefor and use thereof, and a method for the preparation of isobutylene from halomethane. The catalyst is characterized in that it comprises a carrier and a metallic active component supported on the carrier, wherein the metallic active component comprises zinc oxide and zinc halide. On the basis of the total amount of the catalyst, by weight content, the content of zinc oxide is 0.5%-20%, the content of zinc halide is 10%-50%, and the content of the support is 40%-88%. Compared with the prior art, the catalyst of the present invention can convert halomethane into isobutylene with a high selectivity. With the reaction for preparing of isobutylene by converting bromomethane according to the method of the present invention, the conversion of bromomethane is not less than 90% and the selectivity of isobutylene is not less than 80%.

Provided are a supported catalyst, a preparation method therefor and use thereof, and a method for the preparation of isobutylene from halomethane. The catalyst is characterized in that it comprises a carrier and a metallic active component supported on the carrier, wherein the metallic active component comprises zinc oxide and zinc halide. On the basis of the total amount of the catalyst, by weight content, the content of zinc oxide is 0.5%-20%, the content of zinc halide is 10%-50%, and the content of the support is 40%-88%. Compared with the prior art, the catalyst of the present invention can convert halomethane into isobutylene with a high selectivity. With the reaction for preparing of isobutylene by converting bromomethane according to the method of the present invention, the conversion of bromomethane is not less than 90% and the selectivity of isobutylene is not less than 80%.

A method includes brominating a butanes feed stream including i-butane in a bromination reactor to form a bromination effluent stream including t-butyl bromide. The method includes dehydrobrominating the t-butyl bromide to form isobutylene. Another method includes brominating a mixed pentanes feed stream including i-pentane and n-pentane in a bromination reactor to form a bromination effluent stream including t-pentyl bromide. The method includes dehydrobrominating the t-pentyl bromide to form isoamylene and HBr.

A method includes brominating a butanes feed stream including i-butane in a bromination reactor to form a bromination effluent stream including t-butyl bromide. The method includes dehydrobrominating the t-butyl bromide to form isobutylene. Another method includes brominating a mixed pentanes feed stream including i-pentane and n-pentane in a bromination reactor to form a bromination effluent stream including t-pentyl bromide. The method includes dehydrobrominating the t-pentyl bromide to form isoamylene and HBr.

A method includes brominating a butanes feed stream including i-butane in a bromination reactor to form a bromination effluent stream including t-butyl bromide. The method includes dehydrobrominating the t-butyl bromide to form isobutylene. Another method includes brominating a mixed pentanes feed stream including i-pentane and n-pentane in a bromination reactor to form a bromination effluent stream including t-pentyl bromide. The method includes dehydrobrominating the t-pentyl bromide to form isoamylene and HBr.

The present disclosure provides quantum dot organic ligand and preparation method thereof, quantum dot structure material, quantum-dot-containing layer, and quantum-dot-containing light emitting diode. The quantum dot organic ligand have the following structure R1-(R2).sub.n-R3, wherein R1 is a chelating group capable of chelating with a metal; R2 is a group having a conjugated electron pair, and n is a positive integer; and R3 is organic group. The conjugated electron pair structure of R2 facilitates delocalization of electrons, which can improve the transport and conduction of electrons and/or holes, thereby improving the efficiency of quantum dots and lowering the turn-on voltage.

The present disclosure provides quantum dot organic ligand and preparation method thereof, quantum dot structure material, quantum-dot-containing layer, and quantum-dot-containing light emitting diode. The quantum dot organic ligand have the following structure R1-(R2).sub.n-R3, wherein R1 is a chelating group capable of chelating with a metal; R2 is a group having a conjugated electron pair, and n is a positive integer; and R3 is organic group. The conjugated electron pair structure of R2 facilitates delocalization of electrons, which can improve the transport and conduction of electrons and/or holes, thereby improving the efficiency of quantum dots and lowering the turn-on voltage.

Ethylene is produced from ethanol in a one-step process by reacting ethanol with hydrogen chloride over a catalyst composed of silica alumina catalyst in intimate admixture with activated charcoal.

Ethylene is produced from ethanol in a one-step process by reacting ethanol with hydrogen chloride over a catalyst composed of silica alumina catalyst in intimate admixture with activated charcoal.

A process involving the steps in this order of: providing a waste plastics stream (A) comprising polyvinyl chloride (PVC); (i) supplying the waste plastics stream (A) to a reactor vessel; (ii) subjecting the waste plastics in the reactor vessel to a temperature of 250 C. and 350 C., preferably of 275 C. and 325 C., preferably for a period of 5-30 minutes, under applying a vacuum, preferably of 35 mbar, or using an inert gas sweep, and evacuating the generated hydrogen chloride (B) from the vessel, wherein the PVC is partially dechlorinated to form a waste plastics stream (C) comprising partially unsaturated PVC; (iii) removing the waste plastics stream (C) comprising partially unsaturated PVC from the reaction vessel; and (iv) separating the partially unsaturated PVC from the waste plastics stream to form a dechlorinated waste plastics stream (D).