共查询到17条相似文献,搜索用时 125 毫秒
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环氧乙烷催化水合制乙二醇催化剂研究进展 总被引:2,自引:0,他引:2
介绍了国内外对环氧乙烷催化水合法制备乙二醇的催化剂研究进展情况,评述了各催化剂的特点.并对应用状况进行了分析。认为环氧乙烷催化水合法制乙二醇必将代替非催化水合法,而技术的关键是催化剂的开发。 相似文献
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以环氧乙烷催化水合制乙二醇小试研究所开发出的一系列环氧乙烷均相催化剂和相应的工艺流程为基础,进行放大试验,考察催化剂的放大性能,进一步完善工艺技术。通过放大试验进一步验证了小试试验结果的正确性,并对生产工艺的最优化条件进行了筛选和确定,为下一步进行工业化生产奠定了坚实的基础。 相似文献
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采用悬浮聚合方法合成制备了以碳纳米管或石墨烯复合的强碱性离子交换树脂催化剂,表征发现纳米碳材料可以有效分散于复合型树脂的聚合物基体中,并且由于复合型树脂内添加的纳米碳材料与聚合物碳骨架之间存在较强的空间限制作用,复合树脂的热稳定性和抗溶胀性能均有一定提高,发生热分解起始温度提升近15℃,交换容量提高5倍以上。在小型固定床反应器中对合成的树脂催化剂进行一系列环氧乙烷催化水合反应性能的考评,对比结果发现,进料的水与环氧乙烷物质的量比为10的条件下,石墨烯复合型树脂催化剂的催化活性、选择性及稳定性最好,环氧乙烷转化率大于98%,稳定运行300 h保持乙二醇产品收率在95%以上。 相似文献
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Ji Bong Joo Pil Kim Wooyoung Kim Younghun Kim Jongheop Yi 《Journal of Applied Electrochemistry》2009,39(1):135-140
Carbon-supported Pt catalysts were prepared using NaBH4 as a reducing agent in either ethylene glycol or water for use as a cathode catalyst in PEMFCs (polymer electrolyte membrane
fuel cells). Aqueous NaBH4 solution was used to reduce Pt precursor and to produce the Pt-W catalyst, while Pt-E and Pt-E-base catalysts were synthesized
using NaBH4 in ethylene glycol for the reduction of Pt. Compared to Pt-W catalyst, Pt-E and Pt-E-base catalysts have higher Pt dispersion
and larger EAS (electrochemically active surface area) due to the stabilizing effect of ethylene glycolic NaBH4 solution on Pt particles. In addition, increasing pH of the preparation solution improved the Pt dispersion (Pt-E-base).
In unit cell tests the performance of Pt catalysts decreased in the following order: Pt-E-base > Pt-E > Pt-commercial > Pt-W.
Higher metal dispersion and larger EAS are believed to be responsible for the superior performance of Pt-E catalysts, particularly
Pt-E-base, compared to other catalysts. 相似文献
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Amine compounds, bi-functional compounds (EDTA, ethylene diamine tetra acetic acid type), and Salen compounds were investigated for catalytic hydration of ethylene oxide (EO) to monoethylene glycol (MEG). Many of the catalysts studied are selective for the formation of MEG compared with thermal hydration without any catalyst present. The results of the catalytic hydration with three types of catalysts were rationalized using acid and base catalyzed reaction mechanisms. 相似文献
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国内外环氧乙烷合成乙二醇新技术进展 总被引:6,自引:0,他引:6
介绍了国内外这种新技术的现状以及最新研究进展,重点介绍了催化水合法和碳酸乙烯酯法制乙二醇方面的进展。这2种方法,都已进入了工业化推广阶段,代表了今后乙二醇生产发展的方向。 相似文献
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分别以硼氢化钠和乙二醇为还原剂,经络合还原法制备了炭载钯(Pd/C)催化剂。透射电镜(TEM)和X射线粉末衍射谱(XRD)结果表明,以乙二醇为还原剂制备的Pd/C催化剂中Pd粒子具有较小的粒径、均匀的粒径分布和较大的相对结晶度,Pd粒子的平均粒径和相对结晶度分别为4.2±2 nm和1.88。电化学测试结果显示,以乙二醇为还原剂制备的Pd/C催化剂具有较大的电化学活性面积,对甲酸氧化表现出较高的电催化活性和稳定性。 相似文献
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Comparison with the conventional Ziegler-Natta catalyst TiCl4/MgCl2 (I), the modified supported Ziegler-Natta catalysts (iso-PentylO)TiCl3/MgCl2 (II) and (BzO)TiCl3/MgCl2 (III) were prepared as efficient catalysts for copolymerization of ethylene with 1-octene. The complexes (II) and (III) were desirable for the production of random ethylene/1-octene copolymers coupled with higher molecular weight, higher comonomer incorporation within copolymer chain and good yield even at high temperature 80 °C and fairly low Al/Ti molar ratio of 100. The effects of catalysts ligands, Al/Ti molar ratio, polymerization temperature, as well as concentration of 1-octene on the catalytic activity, molecular weight and microstructure of the copolymer were investigated in detail. The structure and properties of the copolymers were characterized with 13C NMR, GPC, DSC and WAXD. The kinetic results also indicate that these catalysts (II) and (III) show higher catalytic activity and the produced polymers feature higher molecular weight, because of lower ratio of Ktrm/Kp and Ktra/Kp, and higher ratio of Ktra/Ktrm which indicates that chain transfer to cocatalyst is predominant. 相似文献
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研究了丁醇和环氧乙烷在一种新型固体酸催化剂上的醚化反应。结果表明,这种新型固体酸具有很高的催化活性和较窄的相对分子质量分布。采用间歇釜式外循环反应器,在n丁醇∶n环氧乙烷=4∶1(物质的量比)、催化剂的质量为丁醇质量的0.4%、反应温度120℃、操作压力0.2~0.3 MPa的条件下,环氧乙烷的转化率为100%、乙二醇单丁醚的选择性较好。确定了最佳工艺参数并成功地进行了工业放大。 相似文献