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The polycrystalline phase WO_3/g-C_3N_4 was synthesized under stirring using tungstenic acid(H_2WO_4) and graphitic carbon nitride(g-C_3N_4) as raw materials. The catalyst was characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),the Fourier transform infrared spectroscopy(FT-IR),and the Brunauer-Emmett-Teller analysis(BET). The polycrystalline phase WO_3/g-C_3N_4 was determined by XRD technique. The oxidative desulfurization process was investigated using WO_3/g-C_3N_4 as the catalyst, 30% hydrogen peroxide(H202) as the oxidant, and 1-butyl-3-methylimidazolium tetrafluoroborate([bmim]BF4) ionic liquids(ILs) as the extractant. The operating conditions, including H_2WO_4 amount, IL dose, H_2 O_2 volume, temperature, catalyst dosage, and types of sulfur compounds,were systematically researched. The desulfurization rate could reach 98.46% for removing dibenzothiophene(DBT) from the model oil under optimal reaction conditions. In addition, the catalytic activity was slightly decreased after five recycles of catalysts. The reaction kinetics analysis shows that the oxidative desulfurization system was in accord with the first-order reaction kinetics equation. The mechanism of oxidative desulfurization was proposed. 相似文献
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将自制的SO2-4改性硅锆双组份交联累托土固体酸催化剂(SO2-4/SiZrR)用于水杨酸(C7H6O3)和正丁醇(C4H10O)的酯化反应,与传统酯化反应催化剂以及其他交联剂交联的累托土作酯化反应的催化剂相比,SO2-4/SiZrR催化剂有更好的催化活性。考察了影响酯化反应的诸因素,并对产物进行了折光率测试、红外光谱分析。酯化反应的最佳条件为:酸醇比n(C7H6O3)/n(C4H10O)=1/1 65、催化剂占酸投料质量的百分比为w(SO2-4/SiZrR)=6 5%、反应温度120~135℃、反应时间6h,水杨酸的转化率可达86 85%,产物中水杨酸正丁酯的质量分数w(C11H14O3)>99 9%。 相似文献
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分别采用超声波辐照浸渍法和普通浸渍法制备了MnO2/γ-Al2O3催化剂,运用电感耦合等离子体原子发射光谱(ICP-AES)和X射线衍射(XRD)对催化剂进行表征,在空气-异丁醛-MnO2/γ-Al2O3体系中评价其对加氢柴油的氧化脱硫催化性能,并考察了反应温度、异丁醛用量、空气流量、溶剂类型和剂/油体积比对柴油氧化脱硫反应的影响。结果表明,超声波辐照浸渍法制备的MnO2/γ-Al2O3催化剂对柴油氧化脱硫的催化性能明显优于普通浸渍法制备的催化剂。最适宜的催化柴油氧化脱硫反应的条件为:乙腈为溶剂、加氢柴油30 mL、温度35℃、异丁醛20 mmol、空气流量0.06 L/min、超声波辐照浸渍法制备的MnO2/γ-Al2O3催化剂0.08 g、剂/油体积比1/6和催化氧化时间10 min。在此条件下可将柴油硫质量分数从542μg/g 降至31μg/g,柴油脱硫率和回收率分别为94.3%和93.3%。 相似文献
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复合SiO2-WO3催化剂的制备、表征及氧化脱除苯并噻吩性能 总被引:1,自引:0,他引:1
采用溶胶-凝胶法制备了SiO2-WO3催化剂,并采用XRD、FT-IR、BET、TG-DTA等方法对催化剂进行表征。以苯并噻吩(BT)为模型化合物,H2O2为氧化剂,考察了催化剂的活性元素、制备方法、n(W)/n(Si)和焙烧温度对其催化氧化脱硫活性的影响。结果表明,W的引入降低了SiO2的比表面积,SiO2-WO3催化剂中W的主物相为WO3。在以W为活性组元,且n(W)/n(Si)为0.1时,500℃焙烧得到的SiO2-0.1WO3催化剂具有最好的催化脱硫活性。在模拟油20 mL、催化剂SiO2-0.1WO3用量0.04 g、n(H2O2)/n(S)为15.9、乙腈/模拟油体积比0.3、65℃反应60 min的条件下,苯并噻吩模拟油脱硫率可达99.3%。 相似文献
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Zhendong Yu Donghui Wang Suhang Xun Minqiang He Ruliang M Wei Jiang Hongping Li Wenshuai Zhu Huaming Li 《石油科学(英文版)》2018,15(4):870-881
Supported ionic liquid(IL) catalysts [C_nmim]_3PMo_(12)O_(40)/Am TiO_2(amorphous TiO_2) were synthesized through a one-step method for extraction coupled catalytic oxidative desulfurization(ECODS) system. Characterizations such as FTIR, DRS,wide-angle XRD, N_2 adsorption–desorption and XPS were applied to analyze the morphology and Keggin structure of the catalysts. In ECODS with hydrogen peroxide as the oxidant, it was found that ILs with longer alkyl chains in the cationic moiety had a better effect on the removal of dibenzothiophene. The desulfurization could reach 100% under optimal conditions, and GC–MS analysis was employed to detect the oxidized product after the reaction. Factors affecting the desulfurization efficiencies were discussed, and a possible mechanism was proposed. In addition, cyclic experiments were also conducted to investigate the recyclability of the supported catalyst. The catalytic activity of [C_(16)mim]_3 PMo_(12)O_(40)/Am TiO_2 only dropped from 100% to 92.9% after ten cycles, demonstrating the good recycling performance of the catalyst and its potential industrial application. 相似文献
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WO_3/SBA-15催化剂的制备及其氧化脱硫性能 总被引:3,自引:2,他引:1
以介孔SBA-15分子筛为载体,采用两种不同钨源(H_2WO_4和H_2C_2O_4、H_2WO_4和H_2O_2)通过浸渍法制备了WO_3/SBA-15催化剂;采用X射线衍射和傅里叶变换红外光谱法对介孔SBA-15分子筛和WO_3/SBA-15催化剂进行了表征;以硫含量为500μg/g的模拟汽油为原料进行氧化脱硫反应,反应后油相用1-甲基-2-吡咯烷酮萃取,考察了萃取剂用量、催化剂用量、氧化反应温度和反应时间对脱硫率的影响。表征结果显示,WO_3/SBA-15催化剂有规则的二维六方介孔结构,WO_3在载体上高度分散。实验结果表明,以H_2WO_4和H_2C_2O_4为钨源制备的WO_3/SBA-15催化剂的脱硫效果较好,在反应温度320 K、反应时间120 min、模拟汽油60 mL、催化剂用量0 12 g、双氧水0.57 mL、萃取剂与模拟汽油体积比0.50、萃取时间5 min的条件下,脱硫率可达94.05%。 相似文献
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H_2WO_4/GO catalyst was synthesized by the immersion method and was characterized by using X-ray diffraction(XRD), Fourier-transform infrared spectroscopy(FT-IR), scanning electron microscopy(SEM), and nitrogen adsorptiondesorption measurements(BET). The characterization results show that H_2WO_4 has been dispersed on GO(grapheme oxide). H_2WO_4/GO was used as catalyst in the oxidative desulfurization of dibenzothiophene(DBT), with H2 O2 acting as oxidant and acetonitrile acting as extraction agent. The experimental results show that the sulfur removal rate for DBT reach 99.2%, that for 4,6-dimethyldibenzothiophene(4,6-DMDBT) reach 95% and that for benzothiophene(BT) reach 42.8% under the optimal reaction conditions. Meanwhile, the recycled catalysts still exhibits good desulfurization performance after four operating cycles. The high activity and stability of catalysis is attributed to a small dose of H_2WO_4, which is highly dispersed inside the layers of GO. This desulfurization reaction follows the pseudo-first-order kinetics, and the apparent activation energy of the desulfurization reaction is 18.515 kJ/mol, which indicates that the H_2WO_4/GO used as desulfurization catalyst has demonstrated good desulfurization property for DBT. 相似文献
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以N-甲基咪唑氟硼酸盐([HMIM]BF4)和苯丙酸(C9H10O2)为原料合成了[HMIM]BF4/xC9H10O2(x=0.5、1、2)型低共熔溶剂(DESs);对其进行FT-IR、1H NMR和TGA表征分析;将[HMIM]BF4/0.5 C9H10O2低共熔溶剂作为萃取剂和催化剂、H2O2作为氧化剂脱除模拟油中的二苯并噻吩(DBT),分别考察了n(C9H10O2)/n([HMIM]BF4)、反应温度、n(H2O2)/n(S)、低共熔溶剂的加入量和不同含硫化合物对脱硫率的影响。结果表明:在模拟油体积为5 mL、n(C9H10O2)/n([HMIM]BF4)=0.5、反应温度为60 ℃、n(H2O2)/n(S)=8、反应180 min、[HMIM]BF4/0.5 C9H10O2的加入量为1.0 mL的最佳反应条件下,[HMIM]BF4/0.5 C9H10O2对DBT、4,6-二甲基二苯并噻吩(4,6-DMDBT)和苯并噻吩(BT)的脱硫率分别达98.4%、93%和89.6%;红外分析表明DBT与DESs之间存在较强的相互作用,可使DBT的结构发生畸变;在5次循环反应后,[HMIM]BF4/0.5 C9H10O2的脱硫率仍高达90.2%,表明其具有较高的稳定性。 相似文献
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Pd-Fe/α-Al_2O_3催化CO偶联制草酸二乙酯催化剂临氢失活研究 总被引:1,自引:1,他引:0
一氧化碳常压气相催化偶联制草酸二乙酯的反应中,由于氢的引入致使偶联反应催化剂Pd-Fe/α-Al2O3失活。研究了不同氢含量条件下催化剂失活以及失活催化剂再生规律,发现催化剂的失活为可逆的,且失活速率随原料气中氢含量的增加而加快。应用X射线光电子能谱、程序升温还原等方法对催化剂中Pd的形态变化进行了分析,发现临氢失活催化剂比反应后催化剂的Pd2+含量要低得多。结果表明,原料气中氢的存在抑制了二价钯的烷氧基中间体Pd(OC2H5)2在催化剂上的产生,从而抑制了草酸二乙酯的生成,导致了催化剂的失活。 相似文献
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通过加热溶解己内酰胺和对甲苯磺酸的混合物制备CC6H11NO/2TsOH型低共熔溶剂(DESs),并对 C6H11NO/2TsOH进行红外和氢谱分析。以C6H11NO/2TsOH为萃取剂和催化剂,H2O2为氧化剂,催化氧化脱除模拟油中的硫化物。考察了反应温度、n(H2O2)/n(S)、C6H11NO/2TsOH用量和不同硫化物类型对脱硫效果的影响。结果表明:在低共熔溶剂加入量为1.0 g、温度为60 ℃、n(H2O2)/n(S)=4、模拟油体积为5 mL的反应条件下,C6H11NO/2TsOH对二苯并噻吩(DBT)、4,6-二甲基二苯并噻吩(4,6-DMDBT)和苯并噻吩(BT)的脱除率分别为97.32%、86.60%、77.80%;C6H11NO/2TsOH循环使用5次,催化活性无明显下降;动力学分析表明,作用下的氧化脱硫过程符合一级反应动力学。 相似文献
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利用[(C16H33) N(CH3)3]3-[PW12O40]双亲催化剂与H2O2组成的催化氧化体系对汽油进行氧化后,以介孔SiO2为载体等体积浸渍法制备的介孔CuO/SiO2为吸附剂,采用固定床连续流动式吸附脱硫评价装置,考察了CuO/SiO2的CuO负载量、焙烧温度、焙烧时间和吸附温度对汽油脱硫率的影响,并对介孔CuO/ SiO2吸附剂性质进行了XRD表征。结果表明,采用在焙烧温度为400℃、焙烧时间为2.0 h、CuO负载量为2%制备的CuO/SiO2, 在吸附温度为120℃时,汽油氧化-脱硫的脱硫效果较好,汽油脱硫率可达56.82%。 相似文献
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杂多酸对碳四馏份中异丁烯的选择齐聚作用 总被引:1,自引:0,他引:1
本文研究了H_3PW_12O_40、H_4SiW_12O_40和H_3PMo_12O_40等杂多酸及H_3PW_12O_40的Cr~(3+)、La~(3+)、Al~(3+)、Fe~(3+)、Cu~(2+)、Cd~(2+)、Ca~(2+)及Zn~(2+)盐对碳四混合物中微量异丁烯的选择齐聚作用。发现H_3PW_12O_40及上述八种盐都有良好的活性和选择性,其中以Zn~(2+)盐为最佳。在Zn_(3/2)PW_12O_40催化剂上,异丁烯含最约为1%,丁烯-1含量约为59%的C_4混合物原料在反应压力1.5—1.6MPa,反应温度55—70℃和LHSV1.5—2.5h~(-1)条件下进行反应时,出口液中异丁烯含量<0.2%,丁烯-1量大损失<3%。 相似文献
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LaAl_(1/3)Fe_(2/3)O_3催化剂的制备及用于VOCs裂解制备碳纳米管 总被引:4,自引:2,他引:2
用硝酸镧、硝酸铝与硝酸铁作原料,采用柠檬酸法制备了多孔铁铝酸镧催化剂,用XRD与SEM对其结构进行表征。采用LaAl1/3Fe2/3O3催化剂,在973K下,研究了易挥发有机物(碳源)苯、环己烷、正己烷、甲苯、甲醇、丙酮催化裂解制备碳纳米管。结果表明,前3种碳源能高收率制备管径均匀的碳纳米管;甲苯、丙酮裂解得到少量不均匀的碳纳米管;甲醇裂解没有碳纳米管生成。以环己烷为碳源,研究了裂解温度对碳纳米管生成的影响,采用SEM、TEM表征了碳纳米管的形貌。 相似文献
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用初湿浸渍法制备了Pt/CeO_2/Al_2O_3催化剂,在异辛烷中加入噻吩硫(硫含量300μg/g),考察了反应条件和催化剂制备条件对异辛烷蒸汽重整反应的影响。实验结果表明,优化的反应条件为:反应温度800℃、水与原料中碳的摩尔比5.3、异辛烷的重时空速1.0h~(-1);优化的催化剂制备条件为:在γ-Al_2O_3上先负载CeO_2并于450℃焙烧,然后再负载Pt并于600℃焙烧,其中CeO_2和Pt的负载量(质量分数)分别为15%和0.8%。在优化制备条件下制得的Pt/CeO_2/Al_2O_3催化剂对异辛烷蒸汽重整反应具有很好的抗硫中毒性能、活性和稳定性。该催化剂在优化反应条件下进行了100h实验,异辛烷转化率在反应前40h接近100.0%,之后略有下降并稳定在95.0%以上,产物中H_2的摩尔分数约为75.0%、CH_4的摩尔分数约为1.0%。 相似文献