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1.
在本研究中制备了一系列Cu-Cr-Mo-RE/SiO2和Cu-RE/SiO2催化剂。研究结果表明:在Cu/SiO2催化剂中,引进Cr、Mo和稀土氧化物后能显著延长催化剂寿命。这一结果并用XPS光谱对催化剂表面及用TG对催化剂抗结焦性能进行了分析研究结论为:Cu-Cr-Mo-RE/SiO2和Cu-RE/SiO2催化剂的负荷比Cu/SiO2催化剂显著提高。  相似文献   

2.
本文报导了Cu=er-Mo/sio2三元复合催化剂中Cu,Cr,Mo的测定方法,此法简便,快速,获得令人满意结果。  相似文献   

3.
本文在同一条件下分别测试了硫化态的催化剂CoMo/(TiO2-Al2O3)及氨化态的Mo2N催化剂的加氢脱硫和加氢脱氮性能,结果表明,对于噻吩的加氢脱硫反应,硫化态催化剂CoMo/(TiO2-Al2O3)在催化活性及稳定性方面都优于Mo2N,而Mo2N在吡啶的加氢脱氮反应中显示了较大优势.  相似文献   

4.
本文利用中压(3.OMPa)固定床流动反应装置研究了不同Co含量对MoO3/TiO2─Al2O3催化剂加氢脱硫性能的影响.结果表明,少量Co助剂的引入可显著提高催化剂的加氢脱硫活性,但对加氢活性影响较小.Co/Co+Mo原子比在0.25~0.45范围内催化活性最高.  相似文献   

5.
采用气相流动吸附法制TiO2/γ-Al2O3复合载体,浸渍法担载一定量MoO3.用XRD,TPR方法考察了MoO3的分散状态,中压固定床反应装置测定催化剂的噻吩加氢脱硫和环己烯加氢活性.结果表明,TiO2的加入能减弱MoO3与γ-Al2O3间的相互作用,促进MoO3的还原,提高催化剂的加氢脱硫活性.  相似文献   

6.
采用气相流动吸附法制TiO2/γ-Al2O3复合载体,浸渍法担载一定量MoO3或CoO-MoO3.用XRD,LRS和TPR等技术考察了Mo或Co-Mo催化剂的表面结构和还原性能.结果表明,覆盖在γ-Al2O3上的TiO2能减弱MoO3与γ-Al2O3之间的相互作用,明显改善Mo催化剂的表面结构,促进MoO3的还原,适量CoO助剂的加入能促进MoO3在载体表面的分散.  相似文献   

7.
本文研究了Cu—Cr—Mo/SiO2三元复合加氢催化剂的制备工艺和寿命。结果表Cu—Cr—Mo/SiO2三元复合加氢催化剂的制备工艺稳定可靠,切实可行,各元素含量可社控制.在芳香旋硝基化合物加氢还原的反应中,本催化剂性能较现在工业上所采用的改性单铜催化剂有较大提高,一次寿命负荷超过单铜50%以上,最高达176%.  相似文献   

8.
In-SituEpitaxialGrowthofBi-Sr-Ca-Cu-OSuperconductingThinFilmsonSi(100)byrfOf-AxisMagnetronSputeringQianWensheng(钱文生)LiuRong(刘...  相似文献   

9.
H1008相对原子质量    He4003Li6941Be9012B1081C1201N1401O1600F1900Ne2018Na2299Mg2431Al2698Si2809P3097S3207Cl3545Ar3995K3910Ca4008Rb8547Sr8762Cs1329Ba1373Se4496Ti4788V5094Cr5200Mn5494Fe5585Co5893Ni5869Cu6355Zn6539Y8891Zr9122Nb9291Mo9594Tt9891Ru1011Rh1029Pd1064Ag1079Cd1124LaLuHf1785Ta1809W1839Re1862Os1902Ir1922Pt1951Au1970Hg2006Ca6972Ge7261As7492Se7896Br7990Kr8380In1148Sn1187Sb1218…  相似文献   

10.
目前已确定了[(CH3)4Si)、[(CH3)3SiOSi(CH3)3SiO-)]、[(-(CH3)2SiO-)3)、[(-(CH3)2SiO-4)及[(-(CH3)2SiO-)5]在297±2K温度下与OH、NO3根及O3的气态反应的速度常数。它们与OH根NO3根及O3的气态反应的速度常数分别为(单位为cm3/克分子·秒):[(CH3)4Si]:1.00±10-12,<8×10-17,<7×10-21;[(CH3)3SiO(CH3)3〕:1.38×10-12,<8×10-17,<7×10-21;[(-(CH3)2SiO-)3]:5.2×10-13,<2×10-16,<3×10-20;[(-(CH3)2SiO-)4]:1.01×10-12,<2×10-16,<3×10-20;[(-(CH3)2SiO-)5〕:1.55×10-12,<3×10-16,<3×10-20。对于这些化合物的对流层迁移过程,它们与NO3根及O3的反应是无关紧要的。在对流层中,这些易挥发的有机硅化合物因与OH根反应而引起的计算寿命的变化范围为从[(-(CH3)2SiO-)5)的10天到[(-(CH3)2SiO-〕3]的30天。  相似文献   

11.
通过溶胶-凝胶法分别制备了掺杂Fe^3+、Cu^2+的TiO2.以日落黄为目标降解物,研究Fe^3+、Cu^2+掺杂TiO2为催化剂的紫外光催化反应,考察了金属离子的掺杂量、催化剂的加入量、光照时间、溶液pH值、溶液初始浓度对脱色率的影响.结果表明:Fe3+掺杂对提高TiO2光催化活性的效果优于Cu^2+掺杂.在Fe^3+、Cu^2+掺杂比为1.5%,Fe^3+、Cu^2+掺杂催化剂用量分别为0.04、0.1 g/L,紫外光催化降解2 h,pH为10,初始浓度为6 mg/L的日落黄100 mL的条件下,Fe^3+、Cu^2+掺杂的催化剂脱色率分别达92.14%、58.68%.  相似文献   

12.
利用N2物理吸附、XRD和空气热重对Cu-ZnO/Al2O3甘油加氢催化剂在制备过程中物相结构的变化进行了系统的研究.研究结果表明,干燥后催化剂主要由Cu2Zn4Al2(OH)16CO3 4H2O和Cu2(OH)2CO3物相组成,经过600℃焙烧4 h后,催化剂在沉淀过程中生成的Cu2Zn4Al2(OH)16CO3 4H2O和Cu2(OH)2CO3全部分解为CuO.在500℃催化剂具有最大的比表面积(79 m^2/g)和孔容(0.36 cm^3/g).  相似文献   

13.
采用溶胶凝胶法制备了Cu/SiO2催化荆,用浸渍法将Mg元素担载在Cu/SiO2催化荆制得Mg-Cu/SiO2催化荆,研究在NO+CO反应中的催化活性.结果表明,Mg修饰的采用方法(c)制备的Cu/SiO2催化荆,当Cu的含量是载体SiO2质量的2%,Mg的含量是载体SiO2质量的3%时,Mg-Cu/SiO2催化荆活性最高,250℃时NO生成N2的转化率接近100%.  相似文献   

14.
采用原位合成法以碳纳米管(cNTs)为载体制备了Cu2O/CNTs复合催化剂。初步考察了复合催化剂对X-3B溶液的光催化降解性能,并对光催化降解动力学进行了研究。  相似文献   

15.
Diesel emission fluid (DEF) soaking and urea deposits on selective catalytic reduction (SCR) catalysts are critical issues for real diesel engine NH3-SCR systems. To investigate the impact of DEF soaking and urea deposits on SCR catalyst performance, fresh Cu-zeolite catalyst samples were drilled from a full-size SCR catalyst. Those samples were impregnated with DEF solutions and subsequently hydrothermally treated to simulate DEF soaking and urea deposits on real SCR catalysts during diesel engine operations. Their SCR performance was then evaluated in a flow reactor with a four-step test protocol. Test results show that the DEF soaking leached some Cu from the SCR catalysts and slightly reduced their Cu loadings. The loss of Cu and associated metal sites on the catalysts weakened their catalytic oxidation abilities and caused lower NO/NH3 oxidation and lower high-temperature N2O selectivity. Lower Cu loading also made the catalysts less active to the decomposition of surface ammonium nitrates and decreased low-temperature N2O selectivity. Cu loss during DEF impregnation released more acid sites on the surface of the catalysts and increased their acidities, and more NH3 was able to be adsorbed and involved in SCR reactions at medium and high temperatures. Due to lower NH3 oxidation and higher NH3 storage, the DEF-impregnated SCR catalyst samples showed higher NO x conversion above 400 °C compared with the non-soaked one. The negative impact of urea deposits during DEF impregnation was not clearly observed, because the high-temperature hydrothermal treatment helped to remove the urea deposits.  相似文献   

16.
贫燃条件下汽车必地气净化铜基催化剂及催化机理的研究   总被引:1,自引:1,他引:1  
采用具有良好抗湿热稳定性的磷硅铝分子筛SAPD-34作载体,制成用于NOx由低碳烃还原的Cu基催化剂,在模拟贫燃汽车尾气条件下,考察了其催化性能,并对反应机理进行了初步的研究。  相似文献   

17.
催化裂化装置催化剂磁分离技术是从废催化剂中分离出重金属含量低、活性和选择性好的低磁催化剂再利用。该技术可以优化催化过程,改善产品分布,提高轻质油等高附加值产品的收率,同时又可降低生产成本,减少催化剂对环境的污染。由于低磁剂的微反活性、比表面积、重金属含量等较处理前大幅改善,使用后系统催化剂性能明显好转,能显著提高装置轻油收率,并降低催化剂单耗,经济效益也十分明显。催化剂磁分离技术具有工艺简单、投资小、能耗少、过程不使用任何化学品、无环境污染、经济效益显著等优点,具有广阔的应用前景。  相似文献   

18.
制备固体超强酸催化剂S2O82-/TiO2-ZrO2,用于合成乙二酸二丁酯,较系统地研究了该催化剂焙烧温度、用量、酸醇物质的量比、反应时间、反应温度和带水剂用量对酯化反应的影响.实验表明:S2O82-/ZrO2-TiO2是合成乙二酸二丁酯的良好催化剂.在催化剂焙烧温度为500℃,乙二酸为0.2mol时,酸醇的物质的量比为1:4,反应温度为130-135℃,反应时间为90min,催化剂用量为2.0g的优化条件下,乙二酸二丁酯的酯化率达95%.  相似文献   

19.
The heterogeneous UV/Fenton process with the appropriate amount of Fe-Mn-Cu-Y as catalyst was developed and various operation conditions for the degradation of phenol were evaluated. The results indicated that by using the heterogeneous UV/Fenton process, the CODcr removal rate reached almost 100% for wastewater containing phenol. Compared with the homogeneous process, the developed catalyst could be used at wider pH range in the UV/Fenton process. Comparison of various heterogeneous process showed that heterogeneous UV/Fenton process was best. The heterogeneous UV/Fenton process with Fe-Mn-Cu-Y catalyst is highly efficient in degrading various organic pollutants.  相似文献   

20.
INTRODUCTION For the degradation of high concentration wast- ewater with toxic and non-biodegradable pollutants, the UV/Fenton method has been proposed in recent years (Braun et al., 1991; Bossmann et al., 1998). The UV/Fenton system relies mainly on oxidative degradation reactions, where organic radicals are generated by photolysis of the organic substrate or by reaction with hydroxyl radicals. These radical intermediates are subsequently trapped by dissolved molecular oxygen and lea…  相似文献   

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