Dissertation > Mathematical sciences and chemical > Chemistry > Physical Chemistry ( theoretical chemistry ),chemical physics > Chemical kinetics,catalysis > Catalytic > Catalyst

Investigation of Methanol Decomposition with High Activity Metal-based Catalysts

Author WangLiZuo
Tutor ChuWei
School Sichuan University
Course Chemical processes
Keywords Copper-nickel catalyst Preparation Characterization Sol-gel Hydroxide Cerium oxide
CLC O643.36
Type Master's thesis
Year 2006
Downloads 198
Quotes 3
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Hydrogen is an ideal clean fuel, methanol for easy storage, easy to restructure, no sulfur excellent physical and chemical properties and become the preferred chemical hydrogen storage material, methanol chemical plant cleaved into a mixture of H2, CO, materials processing The factory provides a simple and economical H2, CO sources. The methanol cracking as a model reaction, first of all proceed from the basic catalyst preparation conditions, the different carrier catalyst reduction, the active ingredient content, combined with TPR characterization results, more in-depth study copper nickel catalyst on Restoring nature. Proper content of alkali and alkaline earth metal oxide (K2O, CaO, and BaO), and other additives added, it is possible to significantly improve the catalytic activity and selectivity, wherein K2O better catalytic additives, low activation energy, the active sequence K2O> BaO> CaO> MgO. TPR analysis results show that the enhanced interaction between the components of the alkali and alkaline earth metal oxide, such a strong interaction makes the catalytic activity is improved. Different heating rate TPR analysis showed that potassium aids restore lower activation energy of the reaction, and is conducive to the generation of the active species in the catalyst. XRD results show that does not appear obvious diffraction peaks of potassium compounds and additives in the catalytic system evenly dispersed in the amorphous disordered short-range or long-range ordered state. Add a small amount of rare earth metal oxide CeO2 and other additives, the rate of methanol conversion and product selectivity has been markedly improved in copper-nickel catalyst. Study cerium oxide content changes of the catalyst, when the cerium oxide content is 3.0 to 5.0%, the number of the active center of the catalyst up; cerium oxide content of more than 5.0%, the number of the active center of the catalyst decreased slightly. TPR, TPD results indicate that the rare earth oxide added modulating the interaction between the components and improve the performance of the reduction of the catalyst, so that the increase in active species reducible; promote the desorption of CO and H2, CO and H2 easily desorbed from the catalyst, the methanol cracking reactions conducive to the forward direction, resulting in increased catalyst activity. The catalyst prepared by sol-gel method is significantly improved catalytic activity than the loading, the calcination temperature on the catalyst properties affecting about 450 ° C, calcined best. TG-DTG characterization of nitrate decomposition of the active species in 450 ℃ completely, BET, and XRD characterization of instructions in the temperature baking

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