Studies on the Selective Oxidations of Methane and Cellobiose over Grafted Copper and Polyoxometalates-Supported Gold Catalysts

本学位论文由甲烷选择氧化制甲醛、纤维素模型分子纤维二糖选择氧化制葡萄糖酸以及新型N-杂环卡宾稳定下的双亚胺单核铜(I)化合物的合成、表征与有机叠氮化反应的研究三部分组成。 论文开展了含高分散铜物种的CuOx/SBA-15-gra催化剂的制备、表征，及其在甲烷选择氧化反应中的催化性能研究。运用XRD、H2-TPR、UV-Vis以及EPR等手段对以嫁接法制备的CuOx/SBA-15-gra催化剂的表征结果表明，当铜含量≤0.6wt%时催化剂上铜物种主要以孤立的Cu2+形式（≥96%）存在；当铜含量>0.6wt%时，随着铜含量的增加催化剂上孤立的Cu2+减少，聚集态的CuOx小簇增加。CuOx/S...This dissertation is composed of the following three parts: selective oxidation of methane to formaldehyde, selective oxidation of cellobiose to gluconic acid, and synthesis of new mononuclear bis(imino)arylcopper(I) N-heterocyclic carbene complex. The dissertation studied the selective oxidation of methane to formaldehyde over the CuOx/SBA-15 catalysts prepared by a grafting approach (denoted a...学位：理学博士院系专业：化学化工学院化学系_物理化学(含化学物理)学号：2052007015357

Asymmetric Transfer Hydrogenation of Ketones Catalyzed by Chiral Multidentate Aminophosphine Ligands/Iron Cluster

从廉价易得、绿色环保的铁簇合物Fe_3(CO)_(12)出发,开展了其与手性多齿胺膦配体(R,R,R,R)-PN_4H_6原位生成的催化体系在酮; 的不对称转移氢化中的应用研究.通过考察温度、添加剂等影响因素,探索最优的反应条件,并将其进一步应用于多种芳香酮的不对称转移氢化反应,得到高达96; % ee的对映选择性.As one of the most abundant metals on earth, iron is cheap and low toxicity. Herein we reported the asymmetric transfer hydrogenation of (ATH) ketones catalyzed by the system generated in situ from chiral multidentate aminophosphine ligand (R, R, R, R)-PN4H6 and Fe-3(CO)(12). The effects of temperature and additive on the ATH of propiophenone were examined. After optimizing the reaction conditions, we applied the catalytic system to the ATH of various aromatic ketones, obtaining the corresponding optical active alcohols with high enantioselectivities (up to 96% ee).National Natural Science Foundation of China [21173176, 21673190];; Fundamental Research Funds for the Central Universities [20720150040

让城市总体规划更有用

今天这场学术对话的主题是\"让城市总体规划更有用\"。城市总体规划是一个城市全局性、综合性规划,在统筹城乡发展、优化空间开发格局、合理配置空间资源、保障公共利益等方面发挥着战略引领和刚性控制作用,是城市重要的公共政策和指导城市建设的法定依据。无论从城乡规划法律的制度设计还是从城市总体规划的属性来看

Copper grafted on SBA-15 as efficient catalyst for the selective oxidation of methane by oxygen

CuOx/SBA-15 catalysts prepared by a grafting approach (denoted as CuOx/SBA-15-gra) have been characterized and studied for the selective oxidation of methane to formaldehyde by oxygen Our characterizations using XRD H-2-TPR UV-vis and ESR suggest that Cu2+ ions are almost isolated on the surface of SBA-15 at a Cu content 06 wt% decreased the fraction of isolated Cu2+ ions and increased that of aggregated CuOx clusters On the other hand the fraction of isolated Cu2+ ions was much smaller in the CuOx/SBA-15 catalyst prepared by the impregnation method (denoted as CuOx/SBA-15-imp) even with a lower Cu content (0 5 wt%) The CuOx/SBA-15-gra provided significantly higher HCHO selectivity in the selective oxidation of CH4 than the CuOx/SBA-15-imp and the CuOx/SBA-15-gra catalyst with a Cu content of 0 6 wt% showed the best performance for HCHO formation In situ FT-IR spectroscopy of adsorbed CO and XPS measurements suggest the generation of Cu+ after the reaction and the Cu+ site is likely responsible for the activation of oxygen forming an active oxygen species for the selective oxidation of CH4 to HCHO (C) 2010 Elsevier B V All rights reserve

Effects of Ultrasound on Crystallization of Cassava Starch

[目的]为了研究超声波作用对木薯淀粉结结晶结构的影响。[方法]用偏光显微镜对超声波作用后的木薯淀粉进行表征。[结果]超声波处理木薯淀粉的最佳条件为:以浓度5%硫酸钠溶液为溶剂,木薯淀粉悬浮液中淀粉含量为16.7%,功率为400 W,作用时间300 s。经超声作用的木薯淀粉颗粒的偏光十字特征减弱或消失,木薯淀粉颗粒的结晶结构减弱或消失。[结论]超声作用破坏了淀粉的结晶结构,颗粒表面与反应试剂的接触面积增多,从而提高了反应活性。[ Objective ] The research aimed to study the effects of ultrasound on the particle shape of cassava starch. [ Method] Polarizing micro- scope was used to study cassava starch treated by ultrasound. [ Result] The optimum ultrasonic treatment of cassava starch was as follows： 5% sodium sulfate as solvent, content of cassava starch 16.7% , ultrasonic power 400 W and irridation time 300 s. The cross-polarized state of cas- sava starch granules showed weakening or disappearance and cassava starch granules crystal structure reduced or lost. [ Conclusion ] Ultrasonic ir- ridation destroyed the crystalline structure of starch, and increased its contact area of particle surface and reactivity.广西科学基金(桂科基0832010);广西科学研究与技术开发计划项目(桂科能0992028-13);广西高校人才小高地建设创新团队项目(桂教人[2011]47号);广西教育厅项目(201106LX127

Effect of microwave on the crystalline structure of cassava starch granules

利用物理场中微波对木薯淀粉颗粒进行处理,考察微波作用对木薯淀粉结晶形态的影响,通过偏光显微镜和扫描电镜观察作用后的木薯淀粉颗粒的结晶结构的变化。实验结果表明,微波作用木薯淀粉,以水为溶剂,配置木薯淀粉悬浮液的含量12.5%,微波作用时间60s,功率160W时,木薯淀粉状态最佳,此时的木薯淀粉颗粒不仅保持着原木薯淀粉的颗粒形状,无溶胀变大或者出现淀粉凝胶和糊化的现象,并且木薯淀粉颗粒的偏光十字呈现减弱或消失的状态,木薯淀粉颗粒的结晶结构减弱或消失。微波作用破坏了淀粉的结晶结构,使颗粒表面与反应试剂的接触面积增多,从而提高了反应活性。 The effect of microwave on structure of cassava starch granules was investigated by polarizing microscope and scan electrical microscope （SEM）. When a suspension of cassava starch （12.5%） in water was microwave-irradated with power of 160 W over 60 s, a best state of starch was available, in which the original basic structure of cassava starch kept intact. No swelling, gel and gelatinized phenomenon was observed, but crystalline structure of cassava starch granules reduced or lost. The granule surface become rough and uneven. Microwave irradiation destroyed the crystalline structure of starch, leading to the increase of contact area of particle surface and the response to reagents.广西科学基金项目(桂科基0832010);广西科学研究与技术开发计划项目(桂科能0992028-13);广西教育厅项目(201106LX127);广西高校人才小高地建设创新团队资助计划项目(桂教人[2011]47号

Effect of sample pretreatment conditions on the photo-induced formation of peroxide species over La_2O_3

采用原位显微rAMAn光谱技术详细考察了焙烧温度和焙烧时间对lA(OH)3分解制备的lA2O3结构以及过氧物种光诱导生成性能的影响,结果表明,经700℃焙烧所得lA2O3样品较经800℃以上长时间焙烧的样品更有利于过氧物种的生成.对lA(OH)3热分解过程的原位Xrd测试结果表明,焙烧温度需达到近700℃才可使lA(OH)3完全转化为lA2O3.在700℃焙烧的样品上,除了六方相的lA2O3外,还可检出介稳态的立方相lA2O3.经800℃以上长时间(≥5 H)焙烧后,介稳态的立方相lA2O3将转化为稳定的六方相lA2O3物种.在相同的实验条件下,立方相的稀土倍半氧化物较六方相更有利于过氧物种的光诱导生成,其原因可能源于前者含更多氧空位,因而更有利于对分子氧的吸附和活化.In situ microprobe Raman spectroscopy technique was used to study the photo-induced formation of peroxide species on the La2O3 prepared by thermal decomposition La(OH)3, with special attention focused on the effects of calcination temperature and calcination time on the structure and performance of the La2O3 samples for the photo-induced formation of peroxide species.It was found that the sample prepared by calcining La(OH)3 at 700℃ is more favorable to the photo-induced formation of peroxide species than those calcined at the temperature above 800℃ for 5 h.There results can be relating to the formation of La2O3 with different phase structures in the samples calcined under different conditions.The XRD patterns recorded during the La(OH)3 thermal decomposition process indicated that La(OH)3 was completely converted La2O3 at the temperature near 700℃.Both hexagonal and cubic La2O3 were detected on the sample calcined at 700℃.After calcining at the temperature above 800℃ for 5h, the metastable cubic La2O3 would finally convert to hexagonal La2O3 phase which was stable at high temperature.Compared with hexagonal lanthanide sesquioxide(Ln2O3), cubic lanthanide sesquioxide is more favorable to the formation of peroxide specie under the same photo-irradiation condition.This phenomenon can be rational explained by that cubic Ln2O3 has more oxygen vacancies than the hexagonal one and thus is more conducive to the adsorption and activation of molecular oxygen.国家重点基础研究发展计划(2010CB732303); 国家自然科学基金(21173173;21033006;21373169); 教育部创新团队(IRT1036)资

Mononuclear Bis(imino)arylcopper(I) N-Heterocyclic Carbene Complex: Synthesis, Structure, and Reaction with Organic Azide

Mononuclear bis(imino)arylcopper(I) N-heterocyclic carbene compound [(IPM)CuL] {1, L = 2,6-(RN=CH)(2)-4-tBuC(6)H(2), R = 2,6-iPr(2)C(6)H(3), IPM = C[N(iPr)CMe](2)} has been synthesized, structurally characterized, and its reaction with 1-adamantyl azide investigated. The reaction of a less bulky arylcopper(I) compound [(IPM)CuPh] with the azide was also studied. The formation of the corresponding products [(IPM)CuN(1-ad)-NN(L)] (2) and [(IPM)CuN(Ph)NN(1-ad)] (3) (1-ad = 1-adamantyl) reveals an aryl group transfer (L in 2 and Ph in 3) reactivity pattern mediated at Cu-1 with the support of the N-heterocyclic carbene. However, a Cu-N1-ad sigma-bond and a Cu ... N-L weak bond were observed in the structure of 2, significantly different to the bonding in 3 in which a Cu-N-Ph sigma-bond and a Cu ... N1-ad weak bond were indicated. This may suggest an initial N-T (N-T, terminal N atom of the azide) coordination of the azide at the Cu center followed by aryl group transfer to N-T. Complex 2 may undergo further bond rearrangement of the Cu ... N bonds within a pseudo-CuN3 four-membered ring as a result of the large bulk of the ligand L.National Nature Science Foundation of China (NNSFC) [20842006, 20721001, 20423002]; Research Fund for New Teacher of Higher Education ; Chinese Postdoctoral Science Foundation [20090460748]; 973 Program [2007CB815307

棉籽仁壳分离系统改造实践Transformation practice of kernel and shell separation system for cottonseed

棉籽中蛋白质含量丰富，为生产高蛋白质含量棉籽蛋白，对棉籽仁壳分离系统进行改造。通过设计，调整剥壳、筛分、风选系统，对棉籽仁壳分离系统工艺及设备进行优化，得到含壳3%~5%的棉仁过程产品，通过浸出（脱脂脱酚）可得到蛋白质含量为60%~62%的棉籽蛋白产品。该蛋白产品可用于鱼饲料，从而提高棉籽的附加值，促进棉籽加工业的发展。 Cottonseed is rich in protein.In order to produce cottonseed protein with high protein content, the kernel and shell separation system for cottonseed was reformed. Through the design and adjustment of shell stripping, screening and air separation system, the technology and equipment of the kernel and shell separation system for cottonseed were optimized, and cottonseed kernel containing 3%- 5% shell was obtained.Through lixiviating(defatting and degossypoling), cottonseed protein product with protein content 60%-62% was obtained, which could be used as fish feed, thus increasing the added value of cottonseed processing industry