生态化利用油页岩制备白炭黑和氧化铝

利用油页岩为原料,首先采用碱溶-沉淀法制备了白炭黑,降低了油页岩中的SiO₂的含量,具体工艺条件为：NaOH/SiO₂（物质的量）＝4,水/油页岩（质量）＝1,100℃,6 h,粒径≥0.15 mm。然后采用酸浸法,制备了γ-Al₂O₃,降低了油页岩中的Al₂O₃和Fe₂O₃的含量,具体条件为：酸浸液中用NaOH溶液调整到pH＝12.0,过滤分离,再用HCl调整溶液pH＝6.0,使Al₂O₃和Fe₂O₃完全分离。最后得到了含量为71.6％的干酪根,并经FT-IR验证。     

ZrO2(3Y)包裹Al2O3纳米复合粉体的制备

以pH值缓冲溶液为沉淀剂,用非均匀成核和液相共沉淀相结合的方法合成出了ZrO₂（3Y）包裹Al₂O₃纳米复合粉体.用XRD、TEM对所制备粉体进行了表征.研究表明：加入分散剂使Al₂O₃悬浮液的等电点向酸性区移动,Zeta电位绝对值增大,其中pH值为9.56对应的Zeta电位绝对值最大,悬浮液最稳定.Al₂O₃悬浮液pH值为9.5,ZrOCl₂和YCl₃混合溶液浓度为0.2 mol•L^-1时前驱体的收得率最高.600℃煅烧后得到的粉体中只有α-Al₂O₃、t-ZrO₂两种物相,在Al₂O₃颗粒表面附着10 nm左右的ZrO₂（3Y）颗粒.     

Al2O3纳米颗粒对氨水鼓泡吸收过程的强化影响

在试制出了性能稳定的Al₂O₃纳米流体的基础上,通过定氨气流量和定入口压力两种实验方案,验证了Al₂O₃纳米颗粒对氨水吸收过程的强化影响,同时找出了引起强化吸收的两个主要影响因素：纳米流体性能的稳定性和吸收器入口与吸收器内气相界面的压力差。在添加十二烷基苯磺酸钠（SDBS）的情况下,可以获得性能稳定而具有强化吸收效果的Al₂O₃纳米流体,尽管SDBS本身对Al₂O₃纳米流体强化吸收具有抑制作用。较大的压力差下Al₂O₃纳米流体在吸收开始阶段就表现出强化吸收效果。随着氨水浓度的增加,氨水对氨气的吸收潜力减小,而Al₂O₃纳米流体对氨水溶液强化吸收的效果更加明显。对强化现象的可能机理给出了合理解释,为纳米流体对传热传质强化研究提供参考。     

Al2O3/TiO2/M复合膜的制备

利用直流脉冲氧化和交流电沉积,在铝基体表面制备了Al₂O₃/TiO₂复合膜。探讨了Al₂O₃/TiO₂复合膜的形成过程及制备过程的影响因素。通过电沉积在Al₂O₃/TiO₂复合膜上掺杂金属离子来提高复合膜的光催化性能,并用制备的Al₂O₃/TiO₂/M 复合膜光催化降解次甲基蓝。     

Co-M/Al2O3上环己烷的选择性氧化研究

采用溶胶-凝胶法制备了Co-M/Al₂O₃(M=Cu，Zn，Ni)催化剂。在没有任何有机溶剂或助剂的条件下，研究了以空气为氧化剂的环己烷选择性氧化。所制备四种催化剂的活性为Co-Ni/Al₂O₃ >Co/Al₂O₃ >Co-Zn/Al₂O₃ >Co-Cu/Al₂O₃。在Co-Ni/Al₂O₃中Co、Ni的质量分数分别为4.0%和3.0%时活性最好。以Co-Ni/Al₂O₃为催化剂，在4.5 MPa、443 K下反应120 min，环己烷转化率达9.9%，环己酮和环己醇的总选择性达94.6%，n(酮)∶n(醇)为2.8。Co-Ni/Al₂O₃催化剂连续使用五次后活性基本不变。     

铜锰氧化物水煤气变换催化剂的还原与催化性能

以CuSO₄·5H₂O和MnSO₄·H₂O为前驱物,NaOH为沉淀剂,选用共沉淀工艺,添加Al₂O₃、BaO+Al₂O₃、ZrO₂+Al₂O₃或CeO₂+Al₂O₃粉末作为催化助剂,制备了4种铜锰氧化物水煤气高温变换催化剂。X射线衍射分析表明,4种铜锰氧化物催化剂的主要化学成分为氧化铜和氧化锰系化合物以及锰钡、铜锰和铜锰铝复合氧化物;在催化水煤气变换反应(WGSR)后,4种铜锰氧化物的化学成分发生了变化。H2还原实验结果表明,在4种铜锰氧化物中,添加ZrO₂+Al₂O₃的铜锰氧化物H₂还原效率最好;而添加CeO₂+Al₂O₃的铜锰氧化物H2还原效率最小。对WGSR出口气中CO体积分数进行对比分析可知,分别添加Al₂O₃和CeO₂+Al₂O₃铜锰氧化物催化剂的变换活性较好。     

Pd/Al2O3催化剂上CH4选择性还原NO的研究

考察了Pd/Al₂O₃、In/Al₂O₃和Co/Al₂O₃对甲烷选择性还原NO的催化活性。结果表明，采用浸渍法制备的Pd/Al₂O₃、In/Al₂O₃和Co/Al₂O₃三种催化剂，在有氧气氛下，用CH₄作还原剂催化还原NO时，Pd/Al₂O₃催化剂的活性最佳，热稳定性好，在550 ℃，用CH₄选择还原NO，Pd/Al₂O₃催化剂表现出较强的催化能力，NO的转化率达到100%。在高空速实验中，该催化剂亦表现出较高的活性，其活性顺序为Pd/Al₂O₃>In/Al₂O₃>Co/Al₂O₃。实验研究了助催化剂、氧含量以及空速对Pd/Al₂O₃催化剂活性的影响。     

高纯超细氧化铝粉的常压烧结与高压烧结

以高纯超细α-Al₂O₃粉为原料，采用常压、高压烧结制备了高纯Al₂O₃陶瓷。研究表明，在乙醇溶剂中高速球磨可显著降低Al₂O₃粉料的平均颗粒尺寸，提高粉料的比表面积与烧结活性；在4.5 GPa、1230℃高压烧结30 min，制备了相对密度达98.71%的无烧结助剂掺杂的Al₂O₃陶瓷；与常压烧结相比，高压烧结可显著降低烧结温度，提高传质速率，大幅度缩短烧结时间，达到快速、低温烧结的效果；由于相对较低的烧结温度，掺杂微量MgO的Al₂O₃陶瓷在高压烧结中未出现液相，MgO对烧结致密化及Al₂O₃晶粒生长抑制几乎无影响。     

CH4与CO检测气敏元件中催化剂的制备与反应性能研究

实现CH₄和CO的多参数检测，催化剂及其催化反应性能是基础。研究了纳米载体Al₂O₃的制备方法，对其孔径分布和前驱体的颗粒度进行了BET和TEM的测定，对CH₄和CO在Pd/Al₂O₃催化剂上的催化反应性能进行了评价。结果表明,采用共沉淀-凝胶工艺和控制制备条件可以得到适宜孔径的催化剂载体。CH₄和CO在Pd/Al₂O₃催化剂上的催化反应性能有较大的差异。催化反应可以满足对CH₄和CO的多参数检测的需要。     

多孔陶瓷载体氧化铝涂层的研究

分别用纳米γ-Al₂O₃和SB粉制备了多孔陶瓷载体的Al₂O₃涂层。BET法测定了多孔陶瓷载体Al₂O₃涂层改性前后比表面积的变化。由SEM照片观察多孔陶瓷载体涂层改性前后表面和断面的形貌。结果表明，这两种方法对多孔陶瓷载体涂层改性均有效可行。     

Impact of reactive SiO2/Al2O3 ratio in precursor on durability of porous alkali activated materials

This study focuses on the properties of porous alkali activated materials (AAM) involving the reactive phases of the raw materials. Two types of calcined clays (illite – IC and metakaolin – WMK) and aluminium scrap recycling waste (ASRW) were considered as precursors for alkali activation. The porous AAM were obtained using ASRW with a different mass ratio in the mixture design as pore forming agent. Two types of fillers (quartz or dolomite powder) were used in AAM and evaluated. The commercial solution of sodium silicate (Na₂SiO₃+nH₂O) modified by alkali flakes (NaOH) was used as an activating solution. The alkali activation mechanism was investigated using FTIR and XRD. Physical, mechanical and durability properties of the obtained materials were tested. The difference of physical and mechanical properties of the porous AAM was not strongly affected by the reactive SiO₂/Al₂O₃ ratio. The density of the AAM was in the range from 550 to 675 kg/m³ and the total porosity was from 70% to 80% depending on the composition. The compressive strength of the porous AAM was in a range from 1.4 to 2.0 MPa (IC sample series) and from 2.0 to 3.8 MPa (MWK sample series). However, the AAM with high SiO₂/Al₂O₃ ratio (1.0–2.4 for IC sample series) have poor durability while sample series with WMK (reactive SiO₂/Al₂O₃ ratio 0.7–0.8) show satisfactory results regarding to the sulphate resistance and can withstand up to 50 standard freeze-thaw cycles.     

脉冲电沉积制备InSb/Sb超晶格纳米线阵列

采用脉冲电沉积技术在氧化铝模板中制备得到直径60 nm的InSb/Sb超晶格纳米线阵列,并运用扫描电镜、透射电镜和电子能谱仪对其形貌与结构进行了表征与测试。高度有序的InSb/Sb超晶格纳米线长度约为40 μm,其长径比超过600。实验中,通过改变沉积电压与时间达到了对超晶格纳米线组分与结构的控制, 纳米线阵列中In与Sb的原子质量比接近于1/2,在每个周期中,InSb的厚度为12 nm,Sb相似文献   

TiO2纳米管的制备及对O3的催化性能

用水热法制备了高比表面积的TiO₂纳米管，通过TEM、XRD及BET进行物化表征，试验得到外径5～7 nm、壁厚1 nm左右、长200～300 nm、比表面积276 m²·g^-1的锐钛型TiO₂纳米管。试验考察了TiO₂纳米管的吸附性能及对O₃的催化性能和本征反应动力学，结果显示：60 min时O₃/UV/TiO₂纳米管较O₃/UV/P25和O₃/UV对垃圾渗滤液的COD去除率分别提高了20.83%和32.65%；293 K时0.5 g TiO₂纳米管对COD的最大吸附量为P25的1.34倍，对COD去除率贡献为10.14%； 2 h内O₃/UV/TiO₂纳米管工艺的总反应表观速率常数k分别是O₃/UV/P25工艺的1.19倍和O₃/UV工艺的1.80倍；得出两种催化工艺k-T关系方程，反应表观活化能E_a,nanotube比E_a,P25降低了2.925 kJ·mol^-1。     

Carbothermal Synthesis of the Nanostructures of Al2O3 and ZnO

Nanostructures of Al₂O₃ and ZnO have been synthesized by a carbothermal route involving the reaction of the metal or the metal oxide with carbon. In the case of Al₂O₃, nanowires and nanotubes are obtained starting with Al metal and active carbon or graphite. ZnO nanowires are obtained by the reaction of zinc oxalate or ZnO with active carbon or multiwalled carbon nanotubes. The Al₂O₃ and ZnO nanostructures obtained have been characterized by X-ray diffraction, electron microscopy and photoluminescence spectroscopy. These nanostructures are likely to be of use as catalyst supports and in other technological applications.     

Porous Al2O3 ceramics with directional gradient pore structure modified by cobweb-bridged WO3 nanowires for oil/water emulsions separation

A novel Al₂O₃ ceramic membrane modified by cobweb-bridged WO₃ nanowires was successfully fabricated for oil/water emulsions separation. Freeze-casting was employed to obtain directional gradient Al₂O₃ porous ceramics at first. Then, the cobweb-bridged WO₃ nanowires were successfully introduced into the separation layer by in-situ hydrothermal synthesis to construct the WO₃ nanowires/Al₂O₃ membrane. Results showed that WO₃ nanowires increased the surface roughness from 45.9 nm to 54.8 nm, the instantaneous water contact angle (WCA) and underwater oil contact angle (UOCA) reached the optimum values of 8.5° and 157.8°, respectively. Construction of cobweb-bridged WO₃ nanowires not only achieved a high separating efficiency of oil/water emulsions up to 92.35%, but also maintained high permeation fluxes at around 1600 L/m²·h·bar. After 10 cycles, the separation efficiency of the membrane remained above 90%. Moreover, the WO₃ nanowires/Al₂O₃ membrane still maintained underwater superoleophobicity after being immersed in strongly acidic, alkaline, and saline solutions, showing a high UOCA above 150° for all tested oil. The WO₃ nanowires/Al₂O₃ membrane is promising in oil/water emulsions separation application for its high separation efficiency, durability, and excellent chemical stability.     

Controlled synthesis of carbon nanocables and branched-nanobelts

Two kinds of new morphology of carbon nanomaterials, carbon nanocables and branched-nanobelts can been produced by pyrolyzing ethylene glycol monvethyl ether (CH₃CH₂OCH₂CH₂OH) with Fe as catalyst at 650-700 °C. The carbon nanocables are made of two parts, the interior carbon nanowires encapsulated in the outer carbon nanotubes. For the nanocables, HRTEM images reveal that the crystallinity of the outer carbon nanotubes is better than that of the interior carbon nanowires. HRTEM image shows that the junctions of the branched-nanobelts are composed of graphitic layers that are almost perpendicular to the respective axis of the branched-nanobelts. The catalysts, temperature and reaction time were investigated. The possible growth mechanism for the as-synthesized carbon structures is discussed.