与铂基催化剂相比,金(Au)因其价格低和抗毒化性能强而在甲醇燃料电池催化剂的设计中引起了大家的广泛关注。采用尿素-过氧化氢溶液为原料,辅助合成了西兰花状金@金-尿素络合物核壳复合物(简写为Au@urea),合成过程中不需要添加任何表面...与铂基催化剂相比,金(Au)因其价格低和抗毒化性能强而在甲醇燃料电池催化剂的设计中引起了大家的广泛关注。采用尿素-过氧化氢溶液为原料,辅助合成了西兰花状金@金-尿素络合物核壳复合物(简写为Au@urea),合成过程中不需要添加任何表面活性剂。在制备过程中,尿素-过氧化氢溶液既可作为还原剂,又为Au纳米颗粒提供了壳层原料。表征结果表明,Au@urea由平均粒径约100 nm的金纳米颗粒组成,金纳米颗粒表面被[Au(urea)_(4)]Cl_(3)·2H_(2O)层包裹。将合成的Au@urea复合物作为电催化剂应用于甲醇氧化反应,在0.5 M KOH和1.0 M CH_(3)OH的电解液中,0.2 V(vs.SCE)电位下的电流密度为15 mA·cm^(-2),高于大多数报道的纳米金基催化剂。此外,由于壳层的存在,Au@urea复合物在甲醇氧化反应中也具有比较好的稳定性。展开更多
以费-托合成馏分油为原料,采用梯度冷却尿素络合法对正构烷烃进行分离,生产煤基费-托合成液体石蜡,考察了降温速率和络合反应条件对正构烷烃分离效果的影响,并采用气相色谱-质谱联用仪、详细烃组成分析等方法对产物的组成进行分析,结果...以费-托合成馏分油为原料,采用梯度冷却尿素络合法对正构烷烃进行分离,生产煤基费-托合成液体石蜡,考察了降温速率和络合反应条件对正构烷烃分离效果的影响,并采用气相色谱-质谱联用仪、详细烃组成分析等方法对产物的组成进行分析,结果表明:当反应体系的温度由45℃以1℃min的速率下降至25℃,尿素异丙醇水溶液与油的质量比为10∶1,尿素、异丙醇、水的质量比为38∶40∶22时,经馏分切割得到的重质液体石蜡中正构烷烃质量分数为93%左右,其各项性质满足NB SH T 0416—2014质量标准要求;与传统冷却尿素络合法相比,梯度冷却尿素络合法的液体石蜡产品纯度和正构烷烃回收率均大幅提高。展开更多
Urea- adduct paper chromatography has been applied in organic geochemistry for separating branched/cyclic hydrocarbons from n-alkanes in sedimentary rocks and oils.The adduct reaction is made in urea adsorbed on the p...Urea- adduct paper chromatography has been applied in organic geochemistry for separating branched/cyclic hydrocarbons from n-alkanes in sedimentary rocks and oils.The adduct reaction is made in urea adsorbed on the paper, and then developed by TLC(thin layer chromatography) technique. Experiments show that this method is of good efficiency. The whole procedure is simple and easily handled. This method is recommended for GC and GC-MS identification of organie components.展开更多
Alginate-Cu(Ⅱ）complex beads or membranes were prepared for removal of urea.The mechanism of sorption of urea was identified by UV-Visible spectra,FT-IR spectra and Far-Infrared spectra.The factors affecting the urea...Alginate-Cu(Ⅱ）complex beads or membranes were prepared for removal of urea.The mechanism of sorption of urea was identified by UV-Visible spectra,FT-IR spectra and Far-Infrared spectra.The factors affecting the urea sorption capacity were discussed in detail.Results showed that the Alginate-Cu(Ⅱ）complex sorbent can sorb about 60 my urea per gram of sorbent at 37℃ and the concentration of urea was 130mg/100ml in Na2HPO4 and NaH2PO4 buffer solution(pH=7.0).展开更多
文摘与铂基催化剂相比,金(Au)因其价格低和抗毒化性能强而在甲醇燃料电池催化剂的设计中引起了大家的广泛关注。采用尿素-过氧化氢溶液为原料,辅助合成了西兰花状金@金-尿素络合物核壳复合物(简写为Au@urea),合成过程中不需要添加任何表面活性剂。在制备过程中,尿素-过氧化氢溶液既可作为还原剂,又为Au纳米颗粒提供了壳层原料。表征结果表明,Au@urea由平均粒径约100 nm的金纳米颗粒组成,金纳米颗粒表面被[Au(urea)_(4)]Cl_(3)·2H_(2O)层包裹。将合成的Au@urea复合物作为电催化剂应用于甲醇氧化反应,在0.5 M KOH和1.0 M CH_(3)OH的电解液中,0.2 V(vs.SCE)电位下的电流密度为15 mA·cm^(-2),高于大多数报道的纳米金基催化剂。此外,由于壳层的存在,Au@urea复合物在甲醇氧化反应中也具有比较好的稳定性。
文摘以费-托合成馏分油为原料,采用梯度冷却尿素络合法对正构烷烃进行分离,生产煤基费-托合成液体石蜡,考察了降温速率和络合反应条件对正构烷烃分离效果的影响,并采用气相色谱-质谱联用仪、详细烃组成分析等方法对产物的组成进行分析,结果表明:当反应体系的温度由45℃以1℃min的速率下降至25℃,尿素异丙醇水溶液与油的质量比为10∶1,尿素、异丙醇、水的质量比为38∶40∶22时,经馏分切割得到的重质液体石蜡中正构烷烃质量分数为93%左右,其各项性质满足NB SH T 0416—2014质量标准要求;与传统冷却尿素络合法相比,梯度冷却尿素络合法的液体石蜡产品纯度和正构烷烃回收率均大幅提高。
文摘Urea- adduct paper chromatography has been applied in organic geochemistry for separating branched/cyclic hydrocarbons from n-alkanes in sedimentary rocks and oils.The adduct reaction is made in urea adsorbed on the paper, and then developed by TLC(thin layer chromatography) technique. Experiments show that this method is of good efficiency. The whole procedure is simple and easily handled. This method is recommended for GC and GC-MS identification of organie components.
文摘Alginate-Cu(Ⅱ）complex beads or membranes were prepared for removal of urea.The mechanism of sorption of urea was identified by UV-Visible spectra,FT-IR spectra and Far-Infrared spectra.The factors affecting the urea sorption capacity were discussed in detail.Results showed that the Alginate-Cu(Ⅱ）complex sorbent can sorb about 60 my urea per gram of sorbent at 37℃ and the concentration of urea was 130mg/100ml in Na2HPO4 and NaH2PO4 buffer solution(pH=7.0).
