17 research outputs found

    Model Catalytic Study of Propane Oxidation

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    丙烷催化转化一直以来都是人们研究的热点。无论是对其进行选择氧化脱氢制丙烯,还是将其完全氧化以提高其燃烧利用率和/或减少其直接排放对大气造成环境污染,都具有重要意义。 本论文首先考察了3%Cs2O/CeO2-2CeF3催化剂的制备方法、CeO2的形貌、催化剂的焙烧气氛及CeF3水解等因素对丙烷氧化脱氢性能的影响。发现不同形貌CeO2具有不同的比表面积和粒径大小,其中比表面积大、粒径小的多面体CeO2和棒状CeO2对丙烷的转化率及丙烯收率都略优于立方体CeO2和商品CeO2,但反应产物仍以CO2为主;CeF3在空气气氛中极易发生水解生成CeO2,而Ar气氛下焙烧3%Cs2O/CeO2-2CeF3...The selective oxidation, as well as catalytic combustion of propane, has been extensively studied for effective use of natural resource and for the elimination of pollutants emitted by automotive exhaust gases and power plants. First part of this thesis, the effects of catalyst preparation methods for 3%Cs2O/CeO2-2CeF3, the morphology of CeO2, the calcination atmosphere and temperature, and the h...学位:理学博士院系专业:化学化工学院_化学学号:2052009015334

    Preparation and Characterization of Sinter-Resistant RhSm2O3/SiO2 Catalyst and Its Performance for Partial Oxidation of Methane to Syngas

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    以乙酰丙酮铑(Rh(acac)_3)和乙酰丙酮钐(Sm(acac)_3)为前驱体,用浸渍法制备了Rh/SiO_2和Rh-Sm_2O_3/SiO_; 2催化剂。采用原位红外光谱、热重分析、低温N_2吸附、X射线粉末衍射、高分辨透射电子显微镜、H_2-程序升温还原和X射线光电子能谱等实验技术对催; 化剂的制备过程,比表面积和物相以及Rh与Sm_2O_3间的相互作用进行了表征,并以甲烷部分氧化制合成气为目标反应对催化剂的稳定性进行了考察。研究; 表明:以Rh(acac)_3和Sm(acac)_3为前驱体采用简单的浸渍法即可制备出Rh平均粒径为2.3; nm且具有良好抗烧结性能的Rh-Sm_2O_3/SiO_2催化剂。在浸渍过程中乙酰丙酮化合物通过与SiO_2表面羟基形成氢键而负载于载体表面。S; m(acac)_3在SiO_2表面的单层负载量(质量分数)约为31%,对应于Sm_2O_3的质量分数约为15%,只要Sm(acac)_3的质量分; 数低于这一阈值,均可保证分解后生成的Sm_2O_3以高分散形式负载于SiO_2上,且不会因高温(800; °C)焙烧而团聚。高分散于SiO_2表面的Sm_2O_3与Rh之间存在强的相互作用,可显著提高Rh的分散度,防止其在高温反应条件下烧结,进而使低; Rh负载量的催化剂表现出良好的甲烷部分氧化制合成气反应活性和稳定性。Rh/SiO2 and Rh-Sm2O3/SiO2 catalysts were synthesized by the conventional impregnation method using rhodium acetylacetonate (Rh(acac)(3)) and samarium acetylacetonate (Sm(acac)(3)) as precursors. The preparation and catalytic properties, as well as the interaction between Rh and Sm2O3, were characterized in detail by in situ infrared spectroscopy (IR), thermogravimetric analysis (TG), N-2 physisorption (Brunauer-Emmett-Teller (BET) method), X-ray powder diffraction (XRD), transmission electron microscopy (TEM), temperature-programmed reduction (H-2-TPR) and X-ray photoelectron spectroscopy (XPS). The performance of the catalysts for the partial oxidation of methane (POM) to syngas was also investigated. The results showed that a sinter-resistant Rh-Sm2O3/SiO2 catalyst with an average Rh particle size of similar to 2.3 nm could be synthesized using the conventional impregnation method with Rh(acac)(3) and Sm(acac)(3) as precursors. The surface silanol groups of SiO2 acted as the centers to interact with M(acac)(3) (M=Rh, Sm) molecules when SiO2 was impregnated in the M(acac)(3) solution, leading to the formation of a hydrogen-bonded M(acac)(3) layer on the SiO2 surface. In this experiment, the monolayer coverage of Sm(acac)(3) on the SiO2 surface was equal to a Sm(acac)(3) loading (mass fraction) of approximately 31%, which in turn corresponded to a Sm2O3 loading of approximately 15%. When a Sm(acac)(3)/SiO2 sample with Sm(acac)(3) loading below 31% was heated in air to approximately 360?, the monolayer Sm(acac)(3) species decomposed into highly dispersed Sm2O3 species on the SiO2 surface, which displayed superior stability against sintering at high temperature. No aggregation of the Sm2O3 species was observed even when the sample was heated to 800 degrees C in air. The strong interaction between the highly dispersed Sm2O3 and Rh plays a key role in increasing the dispersion of Rh species in the catalyst and preventing the Rh species from sintering under high temperature conditions. This factor should also be responsible for the superior activity and stability of the Rh-Sm2O3/SiO2 catalyst with extremely low Rh loading for the catalytic partial oxidation of methane to syngas.国家重点基础研究发展规划项目(2013CB933102),国家自然科学基金(21473144,21373168),国家基础科学人才培养基金项目(J1310024)及教育部创新研究团队项目(IRT_14R31)资

    嗜虫耶尔森氏菌HlyA及HasA外分泌表达系统的构建

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    【目的】构建一株具备外分泌蛋白功能的工程菌,解决杀虫毒素无法由胞内分泌至胞外,无法直接作用于虫体等问题,为松墨天牛防治提供新思路。【方法】本研究先测定从松墨天牛肠道及其生境中分离出的嗜虫耶尔森氏菌(CSLH88)的生长特性及抗性,进而对其进行分子改造。构建HlyA (pGHKW2)以及HasA (pGHKW4)外分泌表达载体,利用电穿孔法将其转入CSLH88菌株,获得能够表达绿色荧光蛋白的工程菌。利用稀释涂板及荧光体式镜检测技术对两个质粒进行遗传稳定性检测,并采用SDS-PAGE及Western blotting技术验证蛋白外分泌功能。【结果】CSLH88菌株培养2–4 h能够进入对数生长期,并对卡那霉素(Kan)敏感。成功构建了含有Kan抗性基因的pGHKW2(GenBank:MK562405)和pGHKW4(GenBank:MK562404)两个外分泌表达载体的CSLH88工程菌株。其中,发现pGHKW4质粒更加适合在嗜虫耶尔森氏菌中稳定遗传。SDS-PAGE及Western blotting检测结果表明HlyA系统无法在CSLH88菌株中将目的蛋白分泌到胞外,而HasA系统则可以有效地发挥外分泌表达功能。【结论】通过对HlyA及HasA两个外分泌表达系统进行研究,从中筛选出HasA型血红素转运系统作为CSLH88菌株的外分泌表达系统,为后续外分泌杀虫毒素蛋白菌株构建以及CSLH88菌株的致病性研究奠定基础。国家重点研发计划课题(2017YFD0600105);;\n国家自然科学基金(31601905);;\n福建省科技厅自然科学基金(2016J01097);;\n福建省科技计划项目(2018N5002);;\n福建农林大学科研基金(xjq201614);福建农林大学林学院林学高峰学科项目(71201800720,71201800753,71201800779);;\n福建省大学生创新创业训练计划项目(201810389102);;\n福建省林业科学研究项目[Minlinke(2017)03]~

    氨辅助浸渍法制备抗烧结Ni/SiO2催化剂及其甲烷二氧化碳重整反应的性能

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    以硝酸镍为前驱盐,商品SiO2为载体,采用氨水辅助浸渍法通过改变n(NH3)/n(Ni)制备了系列Ni/SiO2催化剂,并将其应用于甲烷二氧化碳重整(DRM)制合成气反应,实验结果表明:在浸渍过程中加入氨水可显著改善Ni/SiO2的DRM反应活性、稳定性和抗积碳性。进一步的表征结果表明,随着氨水添加量的增加,催化剂活性相分散度提高,当n(NH3)/n(Ni)≥6后,经800℃焙烧后催化剂上NiO物种的平均粒径小于5nm。通过改变氨水,SiO2,前驱盐的浸渍顺序发现只有用硝酸镍与一定浓度的氨水配成的混合溶液浸渍SiO2才能获得具有良好分散度的Ni/SiO2催化剂。氨水与Ni形成镍氨络合物能够避免在浸渍过程中生成Ni(OH)2沉淀,进而有利于Ni物种在SiO2表面的均匀分散。氨水所形成的碱性环境还可使载体表面Si-O物种部分溶解或“软化”,进而促进Ni物种与载体表面Si-O物种的相互作用,在后续的焙烧过程中生成与SiO2具有较强相互作用的镍物种以及表面镍硅酸盐物种。这些物种具有良好的抗烧结性能,可防止Ni物种在高温下团聚并在600℃以上通H2还原后得到分散性良好且具有较强抗烧结性能的的金属Ni颗粒

    Preparation of Molecularly Imprinted Polymer with 4-Aminoanyipyrine as Template and its Characteristics

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    以4-氨基安替比林为模板分子,甲基丙烯酸为功能单体,十二醇/甲苯为溶剂,采用沉淀聚合法制备了对模板分子具有特异吸附的分子印迹聚合物,考察了制备条件,如溶剂用量、功能单体浓度和交联剂浓度对聚合物吸附性能的影响.静态吸附实验结果表明,在模板分子与功能单体、交联剂摩尔比为1∶5∶20的条件下,可制备出吸附量大且特异性识别能力较佳的分子印迹聚合物,对4-氨基安替比林及其结构类似物安替比林的分离因子为3.72.Molecularly imprinted polymer with 4-Aminoanyipyrine as template was prepared by precipitation polymerization.Methacrylic acid was used as functional monomer and dodecanol/toluene was used as solvent.The effects of reaction conditions,including the volume of solvent,the concentration of functional monomer and crosslinker,on the characteristics of the molecularly imprinted polymer were investigated.The appropriate polymerization conditions occurrs when the molecular ratio of template to monomer to crosslinker is 1∶5∶20.The obtained polymer shows good specific recognition and binding capacity in the rebinding experiments,with the separation factor of 3.72.福建省青年科技人才创新基金(2004J018);; 福建省自然科学基金(E0610030

    抗烧结Rh-SmO/SiO催化剂的制备和表征及其甲烷部分氧化制合成气性能

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    以乙酰丙酮铑(Rh(acac))和乙酰丙酮钐(Sm(acac))为前驱体,用浸渍法制备了Rh/SiO和Rh-SmO/SiO催化剂。采用原位红外光谱、热重分析、低温N吸附、X射线粉末衍射、高分辨透射电子显微镜、H-程序升温还原和X射线光电子能谱等实验技术对催化剂的制备过程,比表面积和物相以及Rh与SmO间的相互作用进行了表征,并以甲烷部分氧化制合成气为目标反应对催化剂的稳定性进行了考察。研究表明:以Rh(acac)和Sm(acac)为前驱体采用简单的浸渍法即可制备出Rh平均粒径为2.3 nm且具有良好抗烧结性能的Rh-SmO/SiO催化剂。在浸渍过程中乙酰丙酮化合物通过与SiO表面羟基形成氢键而负载于载体表面。Sm(acac)在SiO表面的单层负载量(质量分数)约为31%,对应于SmO的质量分数约为15%,只要Sm(acac)的质量分数低于这一阈值,均可保证分解后生成的SmO以高分散形式负载于SiO上,且不会因高温(800°C)焙烧而团聚。高分散于SiO表面的SmO与Rh之间存在强的相互作用,可显著提高Rh的分散度,防止其在高温反应条件下烧结,进而使低Rh负载量的催化剂表现出良好的甲烷部分氧化制合成气反应活性和稳定性。国家重点基础研究发展规划项目(2013CB933102);国家自然科学基金(21473144,21373168);国家基础科学人才培养基金项目(J1310024);教育部创新研究团队项目(IRT_14R31)资助~~

    准原位XPS和HS-LEIS研究载体对PtCu合金纳米催化剂表面组成的影响(英文)

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    Pt是一类高效、稳定的催化剂,但Pt资源短缺且价格昂贵,限制了其广泛商业化应用.合金化可以使Pt的用量大为减少,且往往能显著提高其催化性能,因而广泛应用于多相催化和电催化.其中PtCu合金是一类很有前景的催化剂,Cu资源丰富、价格低廉,不仅降低了成本,而且由于合金效应提高了催化剂的活性和稳定性.由于合金的粒径、形状、组成及结构是影响其催化性能的重要因素,目前研究大多关注这些特征的可控合成.然而,大多工业金属催化剂都是负载于氧化物上以提高催化性能,合金纳米粒子的形貌以及表面组成因与载体作用而发生改变,也就是所谓的载体效应.这体现在金属/氧化物界面处,能够促进金属粒子分散、改变其形貌甚至化学态、进而改变其催化性能,其中最具代表性的金属-载体强相互作用.因此,研究不同氧化物载体上合金催化剂的分散度、表面组成、化学态,特别是不同气氛的影响,对明确影响催化剂性能的关键控制因素非常重要.但是由于多相催化剂的复杂性,且表面灵敏的测试手段很少,目前相关报道还不多.近年发展起来的高灵敏度低能离子散射谱(HS-LEIS)是表面层灵敏的测试技术,可以测定最表面层的组成和含量.本文采用溶剂热共还原法成功制备了均一单相、粒径分布较窄的PtCu合金纳米颗粒,并运用浸渍法将其负载在TiO载体上,以保证载体上纳米粒子组成的均一性.应用准原位X-射线光电子能谱(XPS)和高HS-LEIS对负载的PtCu合金纳米催化剂在不同条件处理后的表面组成和化学状态进行表征,发现催化剂的表面组成、分布、形貌和化学状态显著受到载体和处理条件的影响,同时得到负载和未负载的催化剂表面组成与体相组成关系的相图.结果表明,PtCux/TiO催化剂在连续氧化过程中,Cu被氧化并较好在载体表面铺展,Pt-Cu合金状态被破坏,Pt可能主要形成单一金属的纳米粒子,并在界面处形成Pt.在连续还原过程中,部分被还原的Cu,与Pt形成富Pt合金粒子.催化剂表面层主要是Cu,Pt很少,与体相组成有很大差别,说明载体对Cu的分散起到重要作用.supported by the National Basic Research Program of China(973 Program,2013CB933102);the National Natural Science Foundation of China(21273178,21573180,91545204);Xiamen-Zhuoyue Biomass Energy Co.Ltd~~

    Performance of CO Oxidation over Highly Dispersed Gold Catalyst on TiO_x/SiO_2 Composite Supports

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    负载型Au催化剂中金与载体间存在相互作用,载体性质能够影响Au纳米颗粒分散度及稳定性.本文通过表面溶胶-凝胶(SSg)法制备了TIOX/SIO2复合载体,以期增加氧化物载体表面配位不饱和度从而使其具有较高的金属分散性,并利用低能离子散射(lEIS)谱、X射线光电子能谱(XPS)、X射线衍射(Xrd)、透射电子显微镜(TEM)及n2物理吸附(bET)等手段对载体及催化剂进行表征分析.实验表明TIOX/SIO2复合载体表面TIOX分散性良好,没有形成明显的TIO2晶相,且与SIO2间形成TI―O―SI键.与Au/TIO2相比,Au/TIOX/SIO2催化剂中Au纳米颗粒的分散性更好,因而CO氧化活性显著提高.TIOX/SIO2复合载体上的TIO2膜是Au的主要表面键合位,导致Au与载体间相互作用增强,从而使得Au纳米颗粒抗烧结能力提高,同时催化剂反应稳定性得到改善.Supports have a significant effect on the dispersion and stability of Au nanoparticles because of the support–metal interaction.In the present work, TiOx/SiO2 composite supports were prepared by the surface sol-gel(SSG) method to enhance the binding strength between the metal and the support.The samples were characterized by low-energy ion scattering(LEIS) spectroscopy, X-ray photoelectron spectroscopy(XPS), Xray diffraction(XRD), transmission electron microscopy(TEM), and N2 physisorption(BET).The results showed that the TiOx species in TiOx/SiO2 were highly dispersed on SiO2 with the formation of Ti―O―Si linkages.The catalytic activity and stability for CO oxidation on Au/TiOx/SiO2 were significantly enhanced,because of the better dispersion of Au nanoparticles compared with Au/TiO2.国家重点基础研究发展规划项目(973)(2010CB732303;2013CB933102); 教育部重大研究计划(309019); 国家自然科学基金(20923004;21033006;21073149;21273178); 教育部创新研究团队项目(IRT1036)资助~

    Nursing management of skin and soft-tissue infections complicated with allergic dermatitis caused by catheter insertion during continuous subcutaneous insulin infusion in a patient with latent autoimmune diabetes in adults (1例胰岛素泵导管致皮肤软组织感染伴过敏性皮炎的成人隐匿性自身免疫糖尿病患者的护理经验)

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    This paper summarized nursing measures of skin and soft-tissue infections(SSTIs) complicated with allergic dermatitis caused by catheter insertion during continuous subcutaneous insulin infusion (CSII) in a patient with latent autoimmune diabetes in adults (LADA). Key issues of nursing were as follows: debridement, drainage, systemic and local anti-infection in the early stage of skin care, and negative-pressure wound therapy to improve the wound healing in the later stage of skin care; comprehensive blood glucose management including standardized self-management of insulin pump and monitoring on adverse reactions of clindamycin hydrochloride, levofloxacin and clindamycin; enhancement on psychological nursing and health education. The patient was discharged form hospital and the follow-up results showed that the wound was healed and the blood glucose was well-controlled. (总结1例胰岛素泵导管致皮肤软组织感染伴过敏性皮炎的成人隐匿性自身免疫糖尿病患者的皮肤及伤口护理经验。护理要点包括: 针对伤口护理, 前期给予以清创、引流、全身及局部抗感染, 后期应用负压伤口疗法, 促进伤口愈合; 实施腹针联合激光疗法治疗过敏性皮炎的护理经验; 根据病情全方位血糖管理, 指导患者胰岛素泵规范化自我管理, 监测盐酸克林霉素、左氧氟沙星、克林霉素等消炎药物的不良反应, 预防并发症; 加强心理护理和健康教育。患者经治疗护理16 d后好转出院, 糖尿病足伤口门诊及微信随访, 出院3 d后伤口愈合良好, 血糖控制稳定。

    氨辅助浸渍法制备抗烧结Ni/SiO2催化剂及其甲烷二氧化碳重整反应的性能

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    以硝酸镍为前驱盐、商品SiO2为载体,采用氨水辅助浸渍法通过改变n(NH3)/n(Ni)制备了系列Ni/SiO2催化剂,并将其应用于甲烷二氧化碳重整(DRM)制合成气反应.实验结果表明:在浸渍过程中加入氨水可显著改善Ni/SiO2催化剂的DRM反应活性、稳定性和抗积碳性;随着氨水添加量的增加,催化剂活性相分散度提高,当浸渍液中n(NH3)/n(Ni)≥6时,经800℃焙烧后催化剂上NiO物种的平均粒径小于5nm.通过改变氨水、SiO2、前驱盐的浸渍顺序,发现只有用硝酸镍与一定浓度的氨水配成的混合溶液浸渍SiO2才能获得具有良好分散度的Ni/SiO2催化剂.氨水与Ni形成的镍氨络合物能够避免在浸渍过程中生成Ni(OH)2沉淀,进而有利于Ni物种在SiO2表面均匀分散.氨水所形成的碱性环境还可使载体表面Si—O物种部分溶解或"软化",进而促进Ni物种与载体表面相互作用,在后续的焙烧过程中生成与SiO2具有较强相互作用的Ni物种以及表面镍硅酸盐物种.这些物种具有良好的抗烧结性能,可防止Ni物种在高温下团聚,并在600℃以上通H2还原后得到分散性良好且具有较强抗烧结性能的金属Ni颗粒.国家自然科学基金(21473144)教育部创新研究团队项目(IRT_14R31
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