Preparation Of Furan Derivative From Carbohydrate Biomass By Green Catalysis Progress

In recent years,with the depletion of fossil fuel(coal, oil and natural gas) and the growing demand for energy, biofuels and biochemicals are considered as a promising renewable and sustainable alternative to our limited fossil resources, owning to its preparation using abundant biomass raw materials, especially the inedible biomass. Among all these compounds, furan derivatives(5-hydroxymethylfurfural or furfural) is emphasized and becoming the focus as the renewable biobased platform chemical and feedstock for a variety of high value liquid fuels, polymers, and chemical intermediatesThe major contributions of this dissertation include the following aspects:1. N ovel porous coordinatio n polymer(PCP) catalysts modified with sulfonic acid/phosphotungstic acid(PTA) were prepared by hydrother mal met hod via one-pot self-assembly. The catalysts were characterized by FTIR, XRD, TEM, SEM- EDS, N2 adsorption/desorption, TG, N H3- TPD, etc., and have been syste matically stud ied as solid acids for reproducib le glucose transfor matio n to 5- hydroxymet hylfur fural(HMF) in environme ntally fr iendly solvents. W ith PCP(Cr)-SO3 H·Cr(III) as catalyst, over 99.9% glucose conversion and an excelle nt HMF yie ld of 80.7% were obtained at 180 °C for 4 h in water, wit h THF as the online extraction agent for HMF. In this system, the staple glucose material could successfully substit ute the expensive fr uctose(HMF yie ld = 85.3%). A possib le mechanis m of gluco se conversion and the for mation procedure of byproduct were deduced and analyzed. The catalyst could be easily reused with good reproducib ilit y and low wastage of active metal, showing a good prospect for high value applicatio ns of glucose.2. A mino modified porous organic- inorganic polymer w ith Lew is acid and base sites was prepared via a “one- pot” self- assemb ly hydrotherma l method to transfor m reproducib le glucose to 5- hydroxymethylfur fural(HMF). in pure water(yield=42.2%) or water/THF diphase system(yie ld=65.9%). O ver 99.9% glucose conversion and an excellent H MF yield of 65.9% were obtained at 190 °C in water/THF syste m, of which solvents and catalyst could be recycled easly and reused wit h a better reproduc ibility. Conversio n process could also be realized in the pure water solve nt wit h an acceptable yield of 42.2% and low yie ld of le vulinic acid(0.84%) and formic acid(1.1%) byproducts ind icated that a mino group significant ly reduce product deco mposition, compared w ith repored Lewis- Br?nsted acid bifunct ional catalysts. A possib le conversion mecha nis m and the recycle of catalyst were deduced and realized wit h good reproducib ilit y and low wastage rate of active metal, respective ly.3. A series of cost- effective, renewable and bifunctio nal lignin- based metal heterogeneous catalysts(LS- M) were designed and prepared via a simple met hod by immobilizing waste lignosulfonates(LS) w ith metal ion. Catalysts were characterized by XRD, XPS, SEM, TEM, FI-IR, N H3- TPD, CO2- TPD and TG, and applied in one- pot trans format ion process of cellulose, xylan and correspond ing monoses to important platfor m compound(HMF or furfural) in mixed water/THF syste ms. Pb, Cr, Fe, Zr and Sn were studied as the active metal center and Cr ele me nt was finally confir med as the better one. With LS-Cr as catalyst, the optimized yie lds of H MF(cellulose: 46.3%, glucose: 60.4%, and ma nnose: 68.8%), and fur fural(xyla n: 40.2%, xylose: 73.1%, and arabinose: 51.6%) were obtained, respective ly. The catalyst could be easily recycled with trace wastage of active metal. Research highlights a good prospect for sustainable ut ilization of lignocellulose.