α-MnO2 hollow clews for rechargeable Li-air batteries with improved cyclability

Lithium-air(Li-air) batteries have attracted worldwide attention due to their high energy density(11140 Wh kg-1) comparable to gasoline.In this work,we have synthesized the α-MnO2 hollow clews via a simple method and characterized them by X-ray diffraction and scanning electron microscope.Interestingly,cycle performance of Li-air batteries is improved greatly when using the α-MnO2 hollow clews as the catalyst.The first discharge capacity is 596 mAh g-1,and the charge capacity is 590 mAh g-1 at the current density of 0.1 mA cm-2 between 2.0 and 4.2 V using the Vulcan XC-72 as the carbon material.Additionally,by re-assembling new batteries with the used lithium foil,separators and cathode separately,we find that the cathode is the key role to end the Li-air battery life.     

Catalytic oxidation of phenol in wastewater-A new application of the amorphous Fe78Si9B13 alloy

The amorphous Fe78Si9B13 alloy was used as a heterogeneous Fenton catalyst in the process of phenol degradation.The influences of main operating parameters such as reaction temperature,catalyst amount,hydrogen peroxide dosage and initial pH of solution on phenol degradation rate were investigated.The maximum mineralization of phenol was achieved at 60°C,6 g/L Fe78Si9B13, 0.31 mol/L hydrogen peroxide,with an initial pH of 2.5.More than 99%of phenol was completely removed under the optimum conditions within 10 min for a solution containing 1000 mg/L of phenol.Batch experiments for solutions containing phenol con- centrations ranging from 50 to 2000 mg/L were investigated under the above conditions and the same excellent degradation rate was obtained.The Fe78Si9B13 showed better catalytic activity than iron powder and Fe 2+ .Addition of n-butannol(hydroxyl radical scavenger)decreased the degradation rate of phenol,which demonstrates that hydroxyl radicals were mainly responsible for the removal of phenol.We demonstrated that phenol may be degraded by hydroxyl radicals decomposed by hydrogen peroxide on the surface of Fe78Si9B13 and illustrated the reaction mechanism for this process.This amorphous alloy exhibited high stability in recycling experiments and showed excellent reuse performance even after continuous operations of 8 cycles.     

合成方法对于生物质合成气一步法合成二甲醚催化剂性能的影响

以Cu-ZnO-Fe2O3-ZrO2作为甲醇合成活性组分并以HZSM-5作为甲醇脱水活性组分用3种不同的方法合成了催化剂,对催化剂进行了XRD和BET表征.研究了3种合成方法对于生物质合成气一步法制二甲醚Cu-ZnO-Fe2O3-ZrO2/HZSM-5催化剂催化性能的影响,结果表明,合成方法对于活性组分的分散度有很大的影响,从而进一步影响催化剂对于该反应的催化活性及目标产物的选择性.     

多孔整体催化剂的制备与表征

采用溶胶-凝胶技术,以正硅酸乙酯（TEOS）及高分子量的聚乙二醇（PEG）为主要原料。同时在骨架中引入Al原子,制备了具有大孔、介孔和微孔的相互贯通的多孔整体催化剂载体。采用扫描电镜、物理吸附和红外扫描对载体进行了表征。通过浸渍法负载活性组分铜、锌、锆,制得了催化剂,在固定床微反应器上,对甲醇脱氢反应进行了评价,得到Cu—ZnO—ZrO2型催化剂的催化效果要稍好于其它2种。     

PU延迟性催化剂的合成与应用

实验合成了酸封闭延迟性催化剂,并采用实时粘度测试仪、熟化速度测试仪等手段对三乙烯二胺-异辛酸体系（C2）和三乙烯二胺-甲酸体系（C3）的延迟性催化剂的催化过程和材料物理性能进行了研究。研究结果表明：C2和C3是一种有效的延迟性催化剂,在反应初期显著降低体系粘度,提高体系的流动性能;在反应后期明显加快熟化速度,提高生产效率。C2和C3会降低材料的物理性能,其中C2对材料的物理性能的损伤比C3小。C3严重破坏了材料的耐水解性能。     

TiO2/N可见光光催化降解邻苯二甲酸二甲酯

采用氮掺杂的二氧化钛为催化剂,探索了可见光催化氧化降解邻苯二甲酸二甲酯(DMP)的研究.系统地考察了光催化降解反应中DMP的初始浓度、光照时间、催化剂的量、pH值等因素对邻苯二甲酸二甲酯(DMP)的降解效率及速率的影响;同时对其光降解动力学及光降解过程中的矿化程度进行了一定的分析.结果表明,只有在催化剂和光源同时存在的情况下,DMP才有比较好的降解效果.当DMP的初始浓度为10 mg/L时,在优化条件下,即光催化剂为量1 g/L,pH值为6.20时,在以500W氙灯下进行光照8h,其降解率可达到90%以上.此光催化降解反应过程符合一级反应动力学.     

硫酸铁铵催化合成丁酮乙二醇缩酮

以乙二醇和丁酮为原料,NH4Fe（SO4）2.12H2O为催化剂合成丁酮乙二醇缩酮。通过正交实验得出的适宜反应条件为：固定丁酮的物质的量0.2mol,丁酮与乙二醇的物质的量之比为1.0∶1.6,NH4Fe（SO4）2.12H2O用量占反应物总量的4.3%,反应时间为2.5h,带水剂环己烷用量20mL.在此反应条件下,丁酮乙二醇缩酮的收率为68.1%.     

固载分子筛催化剂催化合成2-戊基蒽醌

用硝酸铵处理沸石分子筛,然后用路易斯酸或有机酸作为固载剂制备了固载型催化剂。用固载型催化剂催化2-(4"-戊基苯甲酰基)苯甲酸(ABB)合成了2-戊基蒽醌(AAQ),并确定了AAQ的最佳合成工艺条件,实验结果表明,AAQ的最佳合成工艺条件为：使用柠檬酸改性Beta沸石分子筛做为催化剂,催化剂浸渍两次,催化剂用量为反应物的20wt％,反应温度300℃,反应时间2 h。此条件下ABB的转化率为98%,得到的AAQ为浅黄色粘稠液体。通过傅立叶变换红外光谱和氢核磁共振光谱确定了AAQ的化学结构。     

相转移催化合成正丁基苯基醚

相转移催化剂是一种良好的催化剂.评述了由聚乙二醇、季铵盐、三乙醇胺、聚氯乙烯固载聚乙二醇树脂、聚苯乙烯固载季铵盐树脂、聚苯乙烯固载吡啶树脂、聚苯乙烯固载多乙烯多胺树脂、聚苯乙烯固载三乙醇胺树脂、聚苯乙烯固载二乙醇胺树脂、聚氯乙烯固载多乙烯多胺树脂催化合成正丁基苯基醚的方法和高分子相转移催化剂的重复使用性能.     

固体超强酸ZrO_2/SO_4~(2-)催化合成富马酸二甲酯

以ＺｒＯ２／ＳＯ２－４固体超强酸催化富马酸与甲醇合成富马酸二甲酯的反应,表征催化剂的物化性质,探讨催化剂制备条件、原料配比、反应时间及催化剂用量等参数对富马酸二甲酯收率的影响．催化剂的重复使用实验表明,ＺｒＯ２／ＳＯ２－４是富马酸二甲酯合成的较适宜的催化剂