[ Instrument R & D of Instrument Network ] Olefin oxidation reaction is an important industrial reaction. Its oxidation products include aldehydes, ketones, 1,2-diketones, epoxy compounds, etc. These oxidation products are used in synthetic fragrances, pharmaceutical intermediates and coatings, Paint and other aspects have extremely wide applications. Traditional olefin oxidation reaction methods (such as: ozone oxidation, Wacker oxidation, Lemieux-Johnson oxidation, olefin epoxidation, etc.) often require the use of precious metal catalysts with low reserves, high prices, and high toxicity, or require equivalent or even excessive heavy metals, high As an oxidant, iodine compounds have harsh reaction conditions, complicated operations, low catalytic activity, and poor selectivity, which severely restrict the application of olefin oxidation reactions in industrial production.
Olefin refers to a hydrocarbon compound containing a C = C bond (carbon-carbon double bond) (alkene bond). It belongs to unsaturated hydrocarbons and is divided into alkenes and cyclic alkenes. According to the number of double bonds, they are called mono-olefins, di-olefins, etc. One of the double bonds is a π bond with higher energy, which is unstable and easily broken, so an addition reaction will occur.
The molecular formula of single-chain olefin is CnH2n, and C2-C4 is a gas at room temperature. It is a non-polar molecule and is insoluble or slightly soluble in water. The double bond group is a functional group in the olefin molecule and has reactivity. It can undergo addition reactions such as hydrogenation, halogenation, hydration, hydrogenation, hypohalogenation, sulfuric acid esterification, epoxidation, polymerization, etc. Rupture, aldehydes, carboxylic acids, etc.
It can be prepared by the reaction of haloalkane with sodium hydroxide alcohol solution, or by the dehydration of alcohol or by the reaction of o-dihaloalkane with zinc. Small molecular olefins are mainly derived from petroleum cracked gas. Cyclic olefins exist more in plant essential oils, and many can be used as spices. Olefin is an important basic raw material in organic synthesis, used for making polyolefin and synthetic rubber.
Recently, a low-carbon catalytic conversion research group led by Yang Yong, a researcher at the Qingdao Institute of Bioenergy and Processes, Chinese Academy of Sciences, based on the preliminary research on high-efficiency and high-stability iron-based nanostructured catalysts, uses renewable biomass as C and N sources and is cheap Fe (NO3) 3 and PPh3 are metal precursors and phosphorus sources. Through a convenient and efficient preparation process, Fe @ NPC-T, a bifunctional iron-based nanostructure catalyst with both oxidizing and Lewis acidity, was constructed. Oxidizing Fe-Nx and Lewis acidic FePO4 double active sites co-exist on the surface of the catalyst, which can realize the efficient oxidation conversion of olefins with tert-butyl hydroperoxide (TBHP) as oxidant and water as solvent under mild conditions.
The study found that the formation of olefins in the middle of epoxy compounds, through the adjustment of reaction conditions, can effectively switch the reaction path between intramolecular Meinwald rearrangement and intermolecular nucleophilic attack, to achieve olefin to ketone and 1,2-dione, etc. Efficient conversion of important synthetic building block molecules. This research work expanded the research of non-noble metal nanostructured catalysts from a single function to a dual-function field, further enriched the catalyst design ideas, and also provided a green and efficient new path for olefin oxidation conversion.
Nanostructure (nanostructure) generally refers to a tiny structure with a size below 100 nm. That is, a new system is constructed or assembled according to certain rules based on the nanometer-scale material units. It includes one-dimensional, two-dimensional, and three-dimensional systems. These material units include nanoparticles, stable clusters or artificial superatoms, nanotubes, nanorods, nanowires, and nanometer-sized holes.
Recently, the team has used ultra-fine and highly dispersed pure phase Ni2P nanostructured catalysts with phosphorus doping strategies to prepare ultra-fine and highly dispersed pure phase Ni2P nanostructured catalysts using cheap, low-toxic, abundant non-precious metal nickel salts and biomass bamboo shoots as raw materials, using phytic acid as a phosphorus source. Achieve efficient and green synthesis of important fine chemicals such as nitrogen-containing heterocycles and alkynyl sulfides.
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