| Summary: | 碩士 === 國立臺灣大學 === 化學研究所 === 106 === Lignins are cross-linked phenolic polymers, whose components are derived from coniferyl, sinapyl and p-coumaryl alcohols. With the depletion of fossil fuels as a source for chemicals, lignin which is one of the main components of vascular plants is considered as a promising renewable alternative source. Various methods have been developed to degrade lignin into high valued chemicals. Oxidative degradation of lignin into small aromatic compounds have been of greater interest than hydro-degradation since oxygen is abundant in air and hydrogen is an energy consumed product. Predominant linkage in lignin is the β-O-4 linkage, which constitutes 45-60%. In this study, 2-phenoxy-1-phenyl ethanol (abbreviated “PP-ol”) and 2-phenoxy-1-phenyl ethanone (abbreviated “PP-one”) were used as the model compounds. Ti-incorporated SBA-15 mesoporous silica materials (Ti-SBA-15) which contain large pores of ca. 6 nm is used as the catalyst. Catalysts were characterized using N2 sorption, XRD and UV-vis spectra. A two-step catalytic reaction was required in order to convert PP-ol into small aromatic compounds. First, PP-ol was converted into PP-one in a Teflon-lined stainless steel reactor, reaction was done at 170 °C for 1 h, using methanol as solvent, H2O2 as oxidant and Ti-SBA-15 as catalyst. After converting PP-ol to PP-one, catalytic reaction was carried out at 110℃, using oxygen as oxidant, and butyronitrile as the solvent. Ti-SBA-15 was found to be efficient in converting PP-one to mainly benzoic acid and phenol. After 48 h reaction, 26% conversion of PP-one was achieved.
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