Al_2O_3@TiO_2复合生物载体的制备及其BSA吸附特性

通过钛酸盐和氧化钛溶胶两种制备途径在氧化铝(Al2O3)支撑体外包覆介孔氧化钛(TiO2)层,分析了这两种途径制备的氧化钛表面结构与性质的差异及其对于BSA蛋白吸附性能的影响。以粒径分别为0.37、10.4和21.8μm的三种氧化铝支撑体作为基材,用XRD、Raman分析了两种路径制备的氧化钛晶型均为锐钛矿相;N2吸脱附分析其比表面积均在(100±10)m2·g-1,两者具有相似的介孔结构。FESEM分析发现钛酸钾溶胶制备的氧化钛的形貌受到支撑体孔径的影响。对于在牛血清蛋白(BSA)吸附实验中,钛酸钾溶胶法包覆的20μm粒径复合载体(SP20@K-TiO2)吸附量为22.18 mg·g-1,高于相同条件下氧化钛溶胶制备的Al2O3@TiO2复合载体。SP20@K-TiO2中TiO2吸附量为150.88 mg·g-1,相比于TiO2粉体,复合载体中TiO2对BSA蛋白吸附的性能得到提升。     

Al2O3溶胶对铝基磷酸盐涂层组织及性能的影响

为提高铝基磷酸盐涂层的耐腐蚀性能和力学性能,通过在铝基磷酸盐涂料中添加 Al₂O₃溶胶,经空气喷涂与热固化得到 Al₂O₃颗粒增强铝基磷酸盐复合涂层,采用 X射线衍射仪（ XRD）、扫描电镜（ SEM）、胶粘拉脱法、维氏硬度、电化学腐蚀试验和模拟海水浸泡试验考察 Al₂O₃溶胶含量对复合涂层微观组织、力学性能和耐腐蚀性能的影响。结果表明： Al₂O₃溶胶在涂层 500 ℃热固化的物相演化为 Al₂O₃溶胶 -AlOOH-Al₂O₃,随 Al₂O₃溶胶含量从 0增加到（γ相）生成的 Al₂O₃颗粒在涂层呈弥散分布;4%,复合涂层的孔隙减少,致密性提高, Al₂O₃颗粒弥散强化作用得到发挥,涂层结合强度由 15 MPa提高为 25 MPa,硬度由 38 HV提高为 65 HV;添加 Al₂O₃溶胶制备得到的铝基磷酸盐复合涂层耐腐蚀性能明显提高,自腐蚀电流密度由 2. 38×10-7 A/cm2下降至 2. 79×10^-8 A/cm²,极化电阻由 1. 95×10⁴ Ω提升至 4. 73×10⁵ Ω。     

聚丙烯酸钠包覆Fe3O4磁性交联聚合物的制备及其对Pb(Ⅱ)和Cd(Ⅱ)的吸附性能

采用溶液分散聚合和Ca²⁺表面交联制备了聚丙烯酸钠包覆Fe₃O₄的磁性交联聚合物（CPAANa@Fe₃O₄）,对其进行了XRD、FT-IR、SEM和TGA等表征。以CPAANa@Fe₃O₄为吸附剂研究了CPAANa@Fe₃O₄对水溶液中Pb²⁺、Cd²⁺的静态吸附,考察了溶液pH、吸附剂投加量、金属离子初始浓度对吸附的影响。结果表明：CPAANa@Fe₃O₄在pH 2～6范围内均具有较好的吸附性能,当吸附剂投加量分别为1.0 g·L^-1和1.6 g·L^-1时对初始浓度分别为200 mg·L^-1的Pb²⁺和100 mg·L^-1的Cd²⁺的去除率达到最大,可使Pb²⁺实现达标排放（GB 8978-1996）;CPAANa@Fe₃O₄对Pb²⁺和Cd²⁺的吸附动力学符合准二级模型,吸附等温线符合Langmuir模型,对Pb²⁺和Cd²⁺的最大吸附量分别为454.55 mg·g^-1和275.48 mg·g^-1。将CPAANa@Fe₃O₄用于处理实际电解矿浆废水,发现能有效吸附其中的Pb²⁺和Cd²⁺,具有潜在实用价值。     

PAN-H1.6Mn1.6O4锂离子筛膜的制备及在卤水中吸附性能

采用亲水的PAN为成膜材料,制备了掺杂H_1.6Mn_1.6O₄的PAN-H_1.6Mn_1.6O₄锂离子筛膜。通过SEM、Li⁺静态吸附实验、（NH₄）₂S₂O₈对锂的洗脱实验和卤水中吸附实验,研究了锂离子筛的添加量对PAN-H_1.6Mn_1.6O₄锂离子筛膜结构、Li⁺吸附-洗脱性能的影响。结果表明,PAN浓度为10%（质量）,H_1.6Mn_1.6O₄的添加量为50%（质量）时,PAN-H_1.6Mn_1.6O₄离子筛膜的吸附量为17.45 mg·g^-1,达到粉末状吸附量的88.0%。以（NH₄）₂S₂O₈为洗脱剂,当浓度为0.3 mol·L^-1、液固比为600:1、时间为12 h时,锂洗脱量为17.23 mg·g^-1,锰溶损率仅为1.14%。在含有Na⁺、K⁺、Mg²⁺和Ca²⁺的罗布泊老卤卤水中,锂离子筛膜对Li⁺有很高的选择性。在卤水中进行10次吸附与解吸循环,吸附量从11.64 mg·g^-1下降到10.94 mg·g^-1,吸附容量仅损失6.0%。总体结果表明亲水性载体对H_1.6Mn_1.6O₄吸附容量影响较小,温和的洗脱剂对锂离子筛膜的化学稳定性有利。     

Al2O3/AC正极选择性电容吸附水中氟离子

氟是人类生命活动必需的微量元素之一,但人体摄入过多的氟元素会引发氟斑牙、骨骼变形等氟中毒现象。本文以活性炭 （AC） 为载体,在多孔Al₂O₃纳米分散液中采用简单超声处理,得到Al₂O₃/AC复合材料。场发射扫描电镜证明Al₂O₃成功负载在AC表面,5% Al₂O₃在AC表面分布均匀。N₂吸-脱附测试结果表明Al₂O₃/AC复合材料的比表面积比AC有明显增加。循环伏安、恒流充放电及电化学阻抗测试结果表明Al₂O₃的掺杂可以改善AC的离子导电性,提高比电容;5% Al₂O₃/AC导电性最佳,比电容最高,在7 mmol·L^-1 NaF溶液中为92 F·g^-1,是AC比电容 （62 F·g^-1） 的1.5倍。以Al₂O₃/AC为正极的电容去离子 （CDI） 脱氟测试,结果表明5% Al₂O₃/AC电极脱氟量最大,达234 μmol·g^-1,远高于纯AC的脱氟量 （115 μmol·g^-1）。此外,5% Al₂O₃/AC电极对F^-的选择性吸附性能良好,在含F^-、Cl^-和SO₄^2-的模拟高氟地下水中采用5% Al₂O₃/AC电极对应的三组CDI池串联,可脱除80%的F^-、25%的Cl^-和56%的SO₄^2-,同时经过十次F^-吸脱附循环后,氟去除率仍可保持81%,证明5% Al₂O₃/AC电极对F^-具有良好的选择吸附性和循环稳定性。该电极材料制备简单,脱氟选择性好,在CDI过程中有望用于高氟地区地下水的净化脱氟。     

海胆状Fe3O4@TiO2磁性纳米介质对Pb2+的选择吸附特性

耦合溶胶-凝胶技术与水热法,制备具有核壳结构的海胆状Fe₃O₄@TiO₂磁性纳米介质（sea urchin magnetic nanoparticles,SUMNPs）。采用TEM、SEM等方法对SUMNPs的形貌等性质进行表征,证实该材料呈现出以Fe₃O₄为核,以TiO₂为壳的海胆状结构,壳层直径约400 nm,比表面积高达236.082 m²·g^-1,表面孔径约6.274 nm。SUMNPs对重金属离子选择吸附的结果表明,基于Pb²⁺离子半径大、电子层数多等物化特点,在Pb²⁺、Cu²⁺、Ni²⁺、Zn²⁺、Cd²⁺ 5种金属离子混合体系中,SUMNPs可以高容量、高选择性快速吸附Pb²⁺,而对其他4种重金属离子几乎无吸附活性。单一Pb²⁺吸附可在5 min内快速平衡,平衡吸附容量为283 mg·g^-1。吸附过程符合Langmuir等温吸附模型,SUMNPs对Pb²⁺的最大饱和吸附容量为458.72 mg·g^-1。经EDTA二钠解吸,NaOH再生后的SUNMPs可以重复使用8次以上。SUMNPs对Pb²⁺具备优异的选择性吸附性能,在处理水体铅污染、恢复水体生态领域具有良好的应用前景。     

Research progress of TiO2?Al2O3 composite support

TiO₂·Al₂O₃多孔复合氧化物是新型的催化剂载体材料,因其在加氢精制工艺上能够显著增加催化剂的脱硫、脱氮活性而逐渐受到重视。本文综述了国内外关于TiO₂·Al₂O₃多孔材料的制备方法,分析了制备方法对材料的比表面积、孔结构、表面酸性等载体性能影响的一般规律。通过对国内外研究者的TiO₂·Al₂O₃合成方法的综合评述,指出了有待发展提高的方向。     

TiO2-Al2O3复合粉体的制备及光催化性能

Al₂O₃陶瓷膜在过滤染料废水过程中容易被染料大分子堵塞,导致Al₂O₃陶瓷膜水通量下降。以钛酸丁酯、异丙醇铝为前驱体,采用溶胶-凝胶法制备Ti(OH)₄-AlOOH复合溶胶,经450 ℃烧成获得TiO₂-Al₂O₃复合粉体。以SEM、纳米粒度/电位仪作为主要表征手段,研究了不同Ti(OH)₄和AlOOH摩尔比对复合溶胶粒径分布的影响,进而探究TiO₂-Al₂O₃复合粉体的光催化性能。结果表明,Ti(OH)₄和AlOOH摩尔比为0~0.4时,随着Ti(OH)₄和AlOOH摩尔比的增大,胶粒的平均粒径从67.5 nm减小到34.0 nm,Ti(OH)₄-AlOOH复合溶胶的电位从43 mV升高至53 mV。当Ti(OH)₄和AlOOH摩尔比为0.4时,复合粉体对结晶紫的去除率高达79.3%,反应速率常数增大到了0.018 min^-1。TiO₂-Al₂O₃复合粉体制备的陶瓷膜能有效降解表面沉积的大分子,解决了陶瓷膜堵塞的问题。     

MnO2-CuO-TiO2共掺Al2O3陶瓷低温烧结和微波介电性能的研究

作为重要微波介质材料之一,Al₂O₃陶瓷介电性能优良,在微波电路方面得到广泛应用。但Al₂O₃陶瓷的烧结温度较高,制备工序需消耗大量能源。低成本降低烧结温度对Al₂O₃陶瓷的进一步发展具有重要意义。本论文通过MnO₂-CuO-TiO₂掺杂实现了Al₂O₃陶瓷的低温烧结,并对其烧结行为和微波介电性能进行了研究。结果表明,MnO₂、CuO、TiO₂的质量分数分别为0.7%、0.5%、0.8%时,复合掺杂可以大幅降低Al₂O₃陶瓷的烧结温度,所获陶瓷具有良好的微波介电性能。在烧结温度为1 250℃时,Al₂O₃陶瓷的密度可达3.92 g/cm³,介电常数ε_r=10.02,品质因子与谐振频率的乘积Q×f值...     

Al2O3/ACF复合电极材料的制备及性能表征

以H₃PO₄预处理后的活性炭纤维(ACF)毡为原料,采用浸渍煅烧法制备Al₂O₃/ACF复合电极材料;通过扫描电镜(SEM)、比表面积及孔径分析仪(BET)、X射线衍射(XRD)、X射线光电子能谱(XPS)、傅里叶红外光谱分析仪(FTIR)对负载Al₂O₃前后活性炭纤维的微观结构与电化学性能进行表征,利用自制的电吸附装置对NaCl模拟废水进行电吸附性能测试。结果表明,采用浸渍煅烧法成功制备了Al₂O₃/ACF复合电极材料,Al₂O₃/ACF复合体表面及孔道中有絮状或颗粒状的Al₂O₃存在,比表面积从1244.37 m²·g^-1降为974.59 m²·g^-1;同时,Al元素含量为1.06%,Al₂O₃以无晶相无定形态存在于纤维表面;Al₂O₃/ACF表面形成一些Al O键的官能团,其比电容比ACF提高76.5%。负载Al₂O₃后的ACF电极材料电吸附性能增强,除盐效率较ACF原样电极提升了2.3倍,且电极具有可再生性。Al₂O₃/ACF复合材料可以作为电极材料用于去除废水中的无机盐离子。     

Ni/Al_2O_3催化剂的CO_2-TPD表征

Ni/Al_2O_3催化剂是甲烷二氧化碳重整反应制取合成气研究最多、最具应用潜力的一种催化剂。通过对催化剂进行CO_2-TPD研究,考察还原态Ni/Al_2O_3催化剂的CO_2脱附特性。结果表明,浸渍法制备的Ni/Al_2O_3催化剂CO_2脱附曲线呈现双峰,分别在(60~65)℃和(350~380)℃出现高低温两个活性位;高温CO_2吸附量为3.0 cm~3·g~(-1),低温CO_2吸附量为24.0 cm~3·g~(-1)。催化剂的CO_2吸附量与其Ni含量无关。考察选用不同载体的CO_2脱附行为,发现以Al_2O_3为载体的催化剂CO_2吸附量是MgO和SiO_2为载体催化剂的2~4倍,以TiO_2为载体的催化剂几乎不吸附CO_2。     

Hydrodesulfurization of dibenzothiophenes over molybdenum catalyst supported on TiO2–Al2O3

Composite types of TiO₂–Al₂O₃ supports, which are γ-aluminas coated by titania, have been prepared by chemical vapor deposition (CVD), using TiCl₄ as a precursor. Then supported molybdenum catalysts have been prepared by an impregnation method. As supports, we employed γ-alumina, anatase types of titania, and composite types of TiO₂–Al₂O₃ with different loadings of TiO₂. We studied the conversion of Mo from oxidic to sulfidic state through sulfurization by X-ray photoelectron spectroscopy (XPS). The obtained spectra unambiguously revealed the higher reducibility from oxidic to sulfidic molybdenum species on the TiO₂ and TiO₂–Al₂O₃ supports compared to that on the Al₂O₃ support. Higher TiO₂ loadings of the TiO₂–Al₂O₃ composite support led to higher reducibility for molybdenum species. Furthermore, the catalytic behavior of supported molybdenum catalysts has been investigated for hydrodesulfurization (HDS) of dibenzothiophene (DBT) and methyl-substituted DBT derivatives. The conversion over the TiO₂–Al₂O₃ supported Mo catalysts, in particular for the 4,6-dimethyl-DBT, is much higher than that obtained over Al₂O₃ supported Mo catalyst. The ratio of the corresponding cyclohexylbenzene (CHB)/biphenyl (BP) derivatives is increased over the Mo/TiO₂–Al₂O₃. This indicates that the prehydrogenation of an aromatic ring plays an important role in the HDS of DBT derivatives over TiO₂–Al₂O₃ supported catalysts.     

TiO_2对Ag/Al_2O_3吸附剂的柴油吸附脱硫性能的影响

采用浸渍法制备不同Ti O2含量的Ag/Ti O2-Al2O3吸附剂,以含硫量为245.36 mg·L-1的商品柴油作为考察对象,常温、常压条件下采用静态评价进行吸附脱硫性能研究。结果表明,经过Ti O2改性的Ag/Al2O3吸附剂柴油吸附脱硫活性有较大幅度提高。通过X射线衍射、N2物理吸附、O2化学吸附和NH3程序升温脱附等研究Ti O2改性剂的影响。关联活性测试和表征结果发现,吸附剂的吸附脱硫活性受吸附剂比表面积、活性金属Ag分散度和吸附剂表面酸协同影响。吸附剂比表面积越大,活性金属Ag分散度越高,吸附剂表面弱酸性位点数量越多,强酸性位点数量越少,吸附剂吸附脱硫活性越高。2%Ag/4%Ti O2-Al2O3的吸附脱硫活性最高,饱和硫容达2.11 mg·g-1。     

Improvement of catalytic activity and sulfur-resistance of Ag/TiO2–Al2O3 for NO reduction with propene under lean burn conditions

Ag-based catalysts supported on various metal oxides, Al₂O₃, TiO₂, and TiO₂–Al₂O₃, were prepared by the sol–gel method. The effect of SO₂ on catalytic activity was investigated for NO reduction with propene under lean burn condition. The results showed the catalytic activities were greatly enhanced on Ag/TiO₂–Al₂O₃ in comparison to Ag/Al₂O₃ and Ag/TiO₂, especially in the low temperature region. Application of different characterization techniques revealed that the activity enhancement was correlated with the properties of the support material. Silver was highly dispersed over the amorphous system of TiO₂–Al₂O₃. NO₃⁻ rather than NO₂⁻ or NOx reacted with the carboxylate species to form CN or NCO. NO₂ was the predominant desorption species in the temperature programmed desorption (TPD) of NO on Ag/TiO₂–Al₂O₃. More amount of formate (HCOO⁻) and CN were generated on the Ag/TiO₂–Al₂O₃ catalyst than the Ag/Al₂O₃ catalyst, due to an increased number of Lewis acid sites. Sulfate species, resulted from SO₂ oxidation, played dual roles on catalytic activity. On aged samples, the slow decomposition of accumulated sulfate species on catalyst surface led to poor NO conversion due to the blockage of these species on active sites. On the other hand, catalytic activity was greatly enhanced in the low temperature region because of the enhanced intensity of Lewis acid site caused by the adsorbed sulfate species. The rate of sulfate accumulation on the Ag/TiO₂–Al₂O₃ system was relatively slow. As a consequence, the system showed superior capability for selective adsorption of NO and SO₂ toleration to the Ag/Al₂O₃ catalyst.     

Tailoring of alumina surfaces as supports for NiMo sulfide catalysts in the ultra deep hydrodesulfurization of gas oil: case study of TiO2-coated alumina prepared by chemical vapor deposition technique

The present paper gives a detailed review of the different studies under investigation in our laboratory concerning the use of TiO₂ and TiO₂–Al₂O₃ composites prepared by chemical vapor deposition (CVD) as support for sulfide catalysts in the HDS of dibenzothiophene (DBT) derivatives. The supports investigated here are: TiO₂ (from Degussa, 50 m²/g), Al₂O₃ (Nikki, 186 m²/g) and TiO₂–Al₂O₃ supports prepared by CVD of TiCl₄ on alumina. Using several characterization techniques, we have demonstrated that the support composite presents a high dispersion of TiO₂ over γ-Al₂O₃ without forming precipitates up to ca. 11 wt.% loading. Moreover, the textural properties of the support composite are comparable to those of alumina. XPS investigations of Mo and NiMo catalysts supported on the different carriers show that Mo-oxide species exhibit a higher degree of sulfidation on the surface of TiO₂ and TiO₂–Al₂O₃ than on alumina. The HDS tests of 4,6-DMDBT under mild operating conditions (573 K, 3 MPa) show that sulfide catalysts supported on the composite support (ca. 11 wt.%) are more active than those supported on to TiO₂ or Al₂O₃. This higher HDS catalytic activity is attributed to the promotion of the hydrodesulfurization pathway, whereby the pre-hydrogenation of one of the aromatic rings adjacent to the thiophenic one may reduce the steric hindrance caused by the two methyl groups adjacent to the sulfur atom during the C–S bond cleavage.     

Support Effects on Thiophene Hydrodesulfurization over Co-Mo-Ni/Al2O3 and Co-Mo-Ni/TiO2-Al2O3 Catalysts

A carbon-based sulfonated catalyst was prepared by direct sulfonation and carbonization （in moderate conditions：200 ＆#176;C, 12 h） of red liquor solids, a by-product of paper-making process. The prepared sulfonated cata-lyst （SC） had aromatic structure, composed of carbon enriched inner core, and oxygen-containing （SO3H, COOH, OH） groups enriched surface. The SO3H, COOH, OH groups amounted to 0.74 mmol·g^-1, 0.78 mmol·g^-1, 2.18 mmol·g^-1, respectively. The fresh SC showed much higher catalytic activity than that of the traditional solid acid catalysts （strong-acid 732 cation exchange resin, hydrogen type zeolite socony mobile-five （HZSM-5）, sulfated zir-conia） in esterification of oleic acid. SC was deactivated during the reactions, through the mechanisms of leaching of sulfonated species and formation of sulfonate esters. Two regeneration methods were developed, and the catalytic activity can be mostly regenerated by regeneration Method 1 and be fully regenerated by regeneration Method 2, respectively.