【作者】 李艳；

【导师】 常杰；

【作者基本信息】 华南理工大学 ， 能源环境材料及技术， 2014， 博士

【摘要】 由于化石资源（石油、煤、天然气等）的不可再生，以及化石资源价格的不断上涨，所以从长远角度来看，化石资源的可利用性在不断的下降。因此，为了降低不可再生的化石资源的消耗速度，我们必须寻找新的解决方法。虽然有很多可再生资源可以用于替代化石资源，如风、水、核聚变及裂变、太阳能等，但是，基于可持续材料转化的工业，如化学工业、工业生物技术以及燃料生产，则依赖于生物质资源，特别是依赖于植物性生物质资源。本论文以可再生资源中低价值的生物质原料高值化转化为目标，以金属卟啉为催化剂对生物质原料选择性催化氧化为路线，制备高附加值化学品（芳香醛）为核心，提出了生物质原料催化氧化制备高价值芳香醛的相关理论。采用Adler法合成了四苯基卟啉，为了提高其水溶性，对四苯基卟啉进行磺化合成了四（4-磺酸苯基）卟啉（TPPS4），然后分别与四种金属盐（Co2+、Ni2+、Cu2+和Zn2+）反应生成了相对应的四（4-磺酸苯基）金属卟啉。四种金属卟啉对酶解玉米秸秆木质素催化氧化降解的效果有着如下的排序：Co(TPPS4)>Cu(TPPS4)>Ni(TPPS4)>Zn(TPPS4)。酶解玉米秸秆木质素选择性催化氧化降解产物主要是高附加值的对-羟基苯甲醛、香草醛和丁香醛。以Co(TPPS4)为催化剂，最佳反应条件是：时间为180min，温度为150℃，Co(TPPS4)用量为0.1000g，氧化剂的用量H2O2为0.5mL。在此条件下，从酶解玉米秸秆木质素催化氧化降解中可以同时得到5.50%的对-羟基苯甲醛，4.68%的香草醛和2.66%的丁香醛，三种芳香醛的总产率是未使用催化剂时的近5倍。因此，以金属卟啉为催化剂对生物质原料选择性催化氧化制备高附加值精细化学品（芳香醛）是切实可行的。以Co(TPPS4)为催化剂，对TCI脱碱木质素、黒液碱木质素、木质素磺酸盐和竹子碱木质素进行选择性催化氧化降解。结果显示Co(TPPS4)可以将碱木质素（TCI脱碱木质素、黒液碱木质素、竹子碱木质素）催化氧化降解，且催化氧化产物是高附加值的芳香醛类化合物，且产物含量符合其原料的组成。但是，在同样的反应条件下，碱木质素反应活性没有酶解玉米秸秆木质素好，主要体现在这三种碱木质素的催化氧化产物中均含有一定量的2,6-二甲氧基-4-乙烯基苯酚。虽然碱木质素反应活性没有酶解玉米秸秆木质素好，但仍然可以得出木质素的紫丁香基单元、愈创木基单元和对-羟基苯丙烷单元的大概含量组成，相对与碱性硝基苯氧化测木质素单元结构的方法，此方法更加绿色环保。同时还可以发现，由于木质素磺酸盐中含大量磺酸根基团，导致空间位阻增大，影响了催化剂与各单元结构侧链的接触，所得催化氧化产物不符合其原料组成，所以Co(TPPS4)对木质素磺酸盐没有完全的催化氧化降解。将生物油有效的分离成三个组分，即水相糖类（左旋葡萄糖为主）、生物油轻组分（低沸点有机酸、醇、酮等）和生物油重组分（愈创木酚等芳香类化合物）。根据三个组分的性质特点分别的进行精制，则会更加合理和有效的利用生物油。提出以Co(TPPS4)为催化剂，对生物油重组分进行选择性催化氧化，可同时得到4.57%香草醛和1.58%的丁香醛，为生物油重组分的开发利用开辟了一条新的道路。选择阿魏酸、4-乙基愈创木酚、H和G型β-O-4高聚物为模型化合物，在Co(TPPS4)/H2O2体系下的氧化降解，揭示了木质素和生物油重组分在Co(TPPS4)/H2O2体系下氧化降解的可能途径。首先，H和G型β-O-4高聚物的β-O-4键的断裂，脱去C-OH形成乙烯基酚类化合物；然后乙烯基酚类化合物的侧链双键发生氧化反应，形成芳香醛或苯基乙酮类化合物；最后少部分芳香醛可能会被进一步氧化成芳香酸。并且发现苯环侧链不饱和的化合物在该体系下可被催化氧化降解，形成其对应的芳香醛类化合物；但是苯环侧链饱和化合物在该体系下则不能被催化氧化降解。将Co(TPPS4)设计成Co(TPPS3C)，即Co(TPPS4)中的一个磺酸苯基由羧酸苯基替代，便于水溶性金属卟啉Co(TPPS4)固载到具有氨基修饰的磁性Fe3O4@SiO2（FS）上。合成的磁性粒子FS和磁性金属卟啉复合物FS-Co(TPPS3C)通过FT-IR、UV、SEM、XRD和VSM等方法进行结构表征验证。以酶解玉米秸秆木质素为原料，金属卟啉Co(TPPS4)没有固载后的磁性金属卟啉复合物FS-Co(TPPS3C)的重复使用性好。固载后的FS-Co(TPPS3C)因磺酸基团的存在，使其更好的分散在水相中，又因磁性载体Fe3O4@SiO2的存在，不仅增加了金属卟啉的重复使用性，又没有改变金属卟啉的催化活性，而且利用磁分离的方法使催化剂得到了快速的分离和简单的回收，十分有效的避免了催化剂回收的繁杂操作。更多还原

【Abstract】 Since fossil resources (oil, coal, natural gas, etc.) are non-renewable and their pricecontinues to rise, the availability of fossil resources will decline constantly in the long-termperspective. Therefore, in order to reduce the rate of consumption of non-renewable fossilresources, we must find the new solutions. Although there are lots of renewable resourceswhich can be used to replace fossil resources, such as wind, water, nuclear fusion and fission,solar, etc. However, based on the sustainable transformation of industrial materials, such aschemical industry, industrial biotechnology and fuel, depend on the biomass resources,especially vegetable biomass resources. Thus, this paper intends to aim at transferringbiomass feedstocks from renewable resources in low-value into high-value chemicals, usingmetalloporphyrin as a catalyst for the selective catalytic oxidation of biomass feedstocks andpreparing the high value-added chemicals (aromatic aldehydes) so as to propose the theoryof catalytic oxidation of preparing high value aromatic aldehydes from biomass feedstock.The improved Adler’s method was used to prepare tetraphenylporphyrin. In order toimprove the water-solubility, the tetraphenylporphyrin was sulfonated into tetrakis-(4-sulfophenyl) porphyrin (TPPS4), and then synthesized into the corresponding tetra-(4-sulfophenyl) metalloporphyrin with the reaction of four kinds of metal salt (Co+2, Ni+2, Cu+2,and Zn2+). The catalytic oxidation effect of degrading the enzymolysis of corn stover ligninusing these metalloporphyrins has the following order: Co(TPPS4)>Cu(TPPS4)>Ni(TPPS4)>Zn(TPPS4). Selective catalytic oxidation products of degrading the enzymolysis of corn stoverlignin are mainly hydroxybenzaldehyde, vanillin and syringaldehyde, which are highvalue-added. Choosing Co(TPPS4) as catalyst, the optimal reaction conditions are:180min,150℃, Co(TPPS4) in an amount of0.1000g, H2O2as oxidant in an amount of0.5mL. Underthese conditions, the catalytic oxidation of lignin from corn stover degradation cansimultaneously obtain5.50%of p-hydroxybenzaldehyde,4.68%of vanillin and2.66%syringaldehyde, the total yield of three aromatic aldehydes is nearly five times as much as theone without catalyst. Therefore, the method of selective catalytic oxidation by usingmetalloporphyrin catalysts to prepare high-value chemicals (aromatic aldehydes) frombiomass feedstock is feasible.Co(TPPS4) was regarded as catalyst, TCI non-alkaline lignin, black liquor alkaline lignin,lignosulfonate and bamboo alkaline lignin were as feedstock. According to the results ofselectively catalytic oxidation degradation of the lignin, alkaline lignin (TCI non-alkalinelignin, black liquor alkaline lignin, and bamboo alkaline lignin) can be degraded to produce high value-added aromatic aldehyde compounds by catalytic oxidation in Co(TPPS4)/H2O2system, and the content of products accord with the composition of alkaline lignin. But, underthe same reaction conditions, the reactivity of alkali lignin was not as good as enzymolysis ofcorn stover lignin. That is the reason that2,6-dimethoxy-4-vinylphenol was presence in theproducts from alkaline lignin catalytic oxidation. Although the reactivity of alkali lignin wasnot as good as enzymolysis of corn stover lignin, but it still can be concluded that alkali lignincontains its base unit (p-coumaryl alcohol, coniferyl alcohol and sinapyl alcohol) by catalyticoxidation in Co(TPPS4)/H2O2system. Comparing with the method of alkaline nitrobenzeneoxidation, the method of measuring lignin unit structure was greener and more environmentalby Co(TPPS4)/H2O2system. At the same time, because lignosulfonate contains a largenumber of sulfonic acid group, which resulted in increased space steric hindrance, finally theproducts didn’t conform to the raw material composition, so lignosulfonate was not fullycatalytic oxidation degraded by Co(TPPS4)/H2O2system.Bio-oil can be separated into three parts, including low-boiling fraction (low-boilingorganic acids, alcohols, ketones, etc.), crude saccharide (mainly levoglucosan), and heavyfraction (guaiacol,2-methoxy-4-methylphenol, etc.). According to the special properties ofthese separated three parts, respectively, the further upgrading will be more reasonable andeffective. We proposed the conversion of heavy fraction of bio-oil (HFBO) to producevaluable aromatic aldehydes by an environmentally friendly method,metalloporphyrins/(H2O2) system catalytic oxidation. High value-added aromatic aldehydeswere selectively produced from heavy fraction of bio-oil in a catalytic oxidation process usingCo(TPPS4) as catalyst.4.57wt.%vanillin and1.58wt.%syringaldehyde were obtained fromcatalytic oxidation of HFBO.Ferulic acid,4-ethyl guaiacol, H-type and G-type polymer were selected to be lignin andheavy fraction of bio-oil model compounds. The model compounds were degradation inmetalloporphyrins/H2O2system to simulate the real lignin and HFBO catalytic oxidationprocess. A possible mechanism of lignin and HFBO oxidation using Co(TPPS4)/H2O2wasproposed by the research of model compounds. Cleavage of β-O-4bonds was the majorpathway that H-type and G-type polymer degraded to produce4-vinylphenolics.[(TPPS4)Co=O]+can transfer the oxygen atom to double bonds of4-vinylphenolics, andforming aromatic aldehyde or phenyl ethyl ketone compounds. The few aromatic aldehydecould be further oxidized to aromatic acid. The results also indicated that unsaturated sidechain of aromatic compounds were apt to produce aromatic aldehydes by catalytic oxidationin Co(TPPS4)/H2O2system. In order to improve the repeated performance of the catalyst, a sulfonic acid phenyl in Co(TPPS4) transformed into a carboxylic acid phenyl, and forming Co(TPPS3C), and thenCo(TPPS3C) was immobilized on the magnetic Fe3O4@SiO2with amino modified (FS). FSand FS-Co(TPPS3C) were characterized by FT-IR, UV, SEM, XRD and VSM. Enzymolysiscorn straw lignin was considered as raw material, Co(TPPS4) can be reused for three times atmost, and catalytic oxidation effect declined gradually. However, FS-Co(TPPS3C) byimmobilized showed high catalytic activity and stability in the recycling experiments. Theimmobilized FS-Co(TPPS3C) was better dispersed in water phase，because of the existence ofsulfonic acid group, which can also enhance the stability of the metalloporphyrin, and keepefficient catalytic activity of the metalloporphyrin. The method of magnetic separation canrealize the rapid and simple separation, and then recycling of catalyst, effectively avoid thecatalyst recycling and complexed operation.更多还原