The usage of zeolite mcm-41(3)
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The usage of zeolite mcm-41(3)
IV. Field of Organic Oxidation
The heterogeneous porous MCM-41 zeolite was used as the catalyst for the oxidation of cyclohexane with hydrogen peroxide. For example, Cr-, Fe - and Ce-are added to make them into modified MCM41 zeolite particle sieve, which can be used to facilitate the oxygen reaction of cycloxane in liquid phase. The reaction is affected by temperature, hydrogen peroxide concentration and the way of adding hydrogen peroxide. Cr-MCM 41 demonstrated the best behavior. The conversion of cyclohexane and the utilization of hydrogen peroxide are affected by the reaction temperature, the concentration of hydrogen peroxide and the way of adding hydrogen peroxide. The conversion of cyclohexane was 33.7%, the selectivity to cyclohexanone and cyclohexanol was 97.2%, and the molecular ratio of cyclohexanone and cyclohexanol was 1.99. When the molar ratio of cyclohexane to hydrogen peroxide is 1: 2 and hydrogen peroxide is added twice at 70 C, the conversion of hydrogen peroxide is 37.1%.
(2) Al-MCM 41 was loaded onto palladium-based Pd (PD), which was used to fuel the burning of CH 4. The aim of this work is to elucidate the behavior of treated palladium catalysts during methane combustion. Palladium was loaded onto the ordered mesoporous molecular sieve Al-MCM-41 (Si: Ai molar ratio 75: 1) as a molecular scaffold. Compared with the untreated, Pa / Al-MCM 41 showed higher activity and better stability. In order to identify the influence of palladium, X ray analysis, N2 absorption analysis, IR high resolution transmission experiment, X ray high molecular energy spectrum and temperature controlled reduction experiment were used. The results show that palladium is active in oxidizing state. After palladium is treated, the acidity of catalyst is enhanced and the degree of dispersion of palladium oxide is increased. This results in an increase in the catalytic activity of the catalyst itself. For the treated palladium catalysts, palladium supported zeolite catalysts have a strong catalytic effect under the dual action of palladium oxide and zeolite. The sintered state of palladium oxide particles attached to the molecular sieve is not an important factor in the stability test. These findings provide useful guidance for the further design of methane combustion catalysts.
epilogue
Although the application research of MCM41 has achieved many results in the field of environmental protection, material development, self-improvement, and organic oxidisation, most of the applications are in the form of load, Modification means that the catalyst or other active material particles are attached or the organic functional groups or inorganic ions are connected to the internal surface area of the channel of MCM-41. Ion exchange and other methods introduced a high content of useful factors into the framework and pores of MCM41 so that the surface modified MCM41 still maintained a good mesopore structure. However, there are few applications to change the internal crystal structure of MCM41 to achieve special functions. Moreover, the introduction of heteroatoms into the framework of MCM-41 makes the zeolite active, but the introduction of heteroatoms is often not high, and the introduction of a large number of heteroatoms will worsen the mesoporous structure, these problems need to be solved.
