排序方式: 共有16条查询结果,搜索用时 15 毫秒
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分别采用浸渍法、化学还原法和超声辅助的浸渍-化学还原法,制备晶态Ni/CNTs、非晶态NiB和NiB/CNTs催化剂,对非晶态NiB/CNTs催化剂热处理使其晶化.表征了催化剂,并考察催化剂的乙炔选择性加氢性能.结果表明非晶态NiB/CNTs合金的催化性能优于晶态Ni/CNTs以及晶化NiB/CNTs催化剂的性能,其在乙炔选择性加氢反应中有较好的稳定性,连续使用650 min后乙炔转化率达80%以上.乙烷选择性随反应进行逐渐下降,最终趋于7.5%;乙烯选择性随反应进行逐渐上升,最终趋于55%. 相似文献
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利用苯胺、曲拉通分别对氨气热处理的碳纳米管进一步功能化,修饰碳纳米管表面,促进碳纳米管分散。采用超声波辅助的浸渍-化学还原法制备非晶态NiB/CNTs合金催化剂,平均粒径为14nm、10nm的非晶态NiB颗粒均匀分布在苯胺、曲拉通处理的碳纳米管表面。苯胺、曲拉通功能化处理使催化剂的Ni负载量分别提高了10.4%、14.6%,同时提高了催化剂的乙炔加氢活性和乙烯选择性。将苯胺和曲拉通的处理效果比较,发现无论是NiB颗粒的分散度还是催化剂的加氢性能,曲拉通处理的效果明显优于苯胺。 相似文献
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TiO2 and N-doped TiO2 films were deposited on the glass substrates by arc ion plating method. The results show that the deposition rate does not change with the increasing deposition time. The increase of mass flow rate of N2 gives rise to the increase of deposition rate. All as-deposited TiO2 and N-doped TiO2 films are amorphous. The anatase TiO2 phase with preferred orientation (101) is acquired by post-annealing at 400 ℃ for 2 h. The incorporation of N into the TiO2 films and the heat treatment extensively shift the band edge to the visible light region. 相似文献
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In a basic solution containing 10 g/L NaOH, the thickness, morphology and corrosion resistance of anodic coatings formed in solutions without and with additions of Na2SiO3, Na2CO3, Na2B4O7 and Na2SnO3 were separately determined and evaluated. The results show that the electrolytes used above take part in the coating formation and the obtained anodic coatings contain elements from the electrolytes. These electrolytes, especially Na2SiO3 and Na2B4OT, contribute to the film thickness. The coating uniformity obtained by addition of Na2SiO3 is the best, while Na2CO3, Na2B4O7 and Na2SnO3 decrease the number of pores per area on the coatings surface though they worsen the uniformity of the anodic coatings. In addition, the anodic coatings formed in solutions with addition of Na2CO3 or Na2SnO3 exhibit loose and net-like structure. Na2SiO3 and Na2B4O7 can significantly improve the corrosion resistance of the anodic coatings while Na2CO3 and Na2SnO3 have minor effects on improving the coating corrosion resistance. 相似文献
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合金元素对氧化膜性能影响很大。分别恒流氧化了纯镁、AZ91HP和Mg-Li合金并测量了氧化膜成分及厚度。EDX分析表明,在Mg—Li合金上形成的氧化膜P含量最高(39.39%),AZ91HP上最低(35.88%);膜厚测量结果为Al和Li分别使氧化膜厚度稍微减少和大大增加。Al和Li元素对氧化膜性能影响可以用Mg^2+、Al^3+和Li^+移动速度不同以及MgO、Al2O3和Li2O的PBR(Pilling—Bedweorth ratio)值不同来解释。 相似文献
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采用化学溶池沉积法在玻璃衬底上制备ZnS薄膜.为了解联氨在沉积过程中的作用,采用金相显微镜、XRD、nkd-薄膜分析系统对薄膜形貌、结构和光学性能进行分析.结果表明:随着联氨浓度的增加,衬底表面形核点数目增加,分布均匀,薄膜颗粒得到细化.结合Zn2+的络合前驱体、络合常数及其三元络合常数计算、氢键及空间位阻等方面的分析,认为会出现3种不同的络合前驱离子,分别为、、.这些Zn2+的前驱体影响着衬底形核点的数目、分布与薄膜的均匀性.在适当条件下,联氨不再起辅助沉积的作用,而是与氨一起形成三元络合配位体系,共同参与沉积.通过改变联氨浓度,可以制备出在550~ 1 000 nm的波长范围内透过率达95%以上、反射率与透过率相对应、均匀平整的非晶薄膜. 相似文献
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Heat treatment of carbon nanotubes (CNTs) was carried out under ammonia atmosphere and then CNTs were modified by Triton x-100 (CNTs-T). Ni-B amorphous alloy catalysts supported on CNTs and CNTs-T were prepared by impregnation-chemical reduction method. The catalysts were characterized by TEM, ICP, XRD, BET and CO chemisorption, and studied in the acetylene selective hydrogenation. The results show that homogeneous Ni-B amorphous particles with mean size about 10 nm are successfully prepared on CNTs-T. Compared with Ni-B/CNTs, nickel loading of Ni-B/CNTs-T is increased by about 14.6%. Furthermore, the activity and selectivity of Ni-B/CNTs-T are much higher than those of Ni-B/CNTs in the acetylene selective hydrogenation under comparative condition. 相似文献