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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Development of Reusable heterogeneous Catalysts for Sustainable formic acid production and methanol utilization

Yuan, Ding-Jier 02 1900 (has links)
The green production of formic acid and utilization of methanol over heterogeneous catalysis system were investigated in this study. The heterogeneous catalysts are widely used in the chemical industry. They offer high stability and reusability which can enhance the production ability and lower the production cost, it can be considered as the sustainable energy solution for the future. In this work, we demonstrated several different heterogeneous catalysts for sustainable formic acid production and methanol utilization, including the heteropoly acid supported mesoporous silica catalysts and multi-function mixed metal oxide catalysts. Detailed characterizations of the final products were carried out by N2 adsorption and desorption, XRD, HR-TEM, SEM, ICP-OES, XANES, NH3- TPD, Raman spectroscopy, and FTIR to identify the chemical properties and physical properties of the catalysts. We obtained 60 % glycerol conversion and 30 % formic acid selectivity with at least 3 rounds of usages in batch system over PV1Mo/SBA-15-p-DS catalyst. Moreover, the continuous methyl formate production with significantly high formation rate (16.7) has been achieved via our CuMgO-based catalysts, and the best Cu5MgO5 catalyst gives more than 80 % methanol conversion with constant selectivity to methyl formate even after 4 catalytic test (more than 200 h), revealing their potential for industrialization. For the methanol utilization reaction, the methanol homocoupling to form dimethoxymethane (DMM) has been investigated. The redox and acidic properties of catalysts both play a critical role in this reaction and the related to different product. The supported V2O5 catalyst achieves the best catalytic performance (62.1 % conversion and 85.6 % DMM selectivity) with a Ce/Al specific ratio of 1. This research not only provided the efficient catalysts for numerous application with high activity, but also discovered the relation between the catalytic performance and the nature of the materials. These findings might further help the researcher to solve the global environmental and energy issues in the near future.
2

Étude de catalyseurs à base d’oxyde de titane et d’oxyde de vanadium sulfatés pour l’oxydation sélective du méthanol en diméthoxyméthane (DMM) / Sulfated vanadia-based and titania-based catalysts for selective oxidation of methanol to dimethoxymethane (DMM)

Zhao, Hongying 28 June 2010 (has links)
Ce travail est en relation avec la thématique "Energies Propres". Le diméthoxyméthane estun composé adapté au stockage de l’hydrogène pour des applications mobiles, de par saforte teneur en hydrogène, sa très faible toxicité et son faible impact sur l'environnement.De ce fait, des catalyseurs mixtes, à base d’oxyde de vanadium et d’oxyde de titanesulfatés ont été préparés et testés dans la réaction d'oxydation sélective du méthanol enDMM, en vue de la production d'hydrogène. Les propriétés acides et redox de surface ontété corrélées aux performances catalytiques. Les mécanismes de réaction et l'identificationdes facteurs limitant l'activité et la sélectivité des catalyseurs ont été aussi étudiés. / This work is related to the subject “Clean Energy”. Dimethoxymethane (DMM) is asuitable H2 storage material for mobile application because of its high content of hydrogen,extremely low toxicity and environmentally benign. Therefore, sulfated vanadia-titania,sulfated binary vanadia-based and titania-based catalysts were prepared and evaluated inthe reaction of selective oxidation of methanol to DMM and further production ofhydrogen. The surface acidic and redox properties of the studied catalysts were correlatedto their catalytic performance. In addition, the reaction mechanisms and the identificationof factors limiting the activity and selectivity of catalysts were also studied.

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