检索结果-南通市图书馆

CuZn/CeO_(2)催化剂在CO_(2)加氢制甲醇中的应用研究

在线全文

学校读者我要写书评

暂无评论

低碳化学与化工 2024年第8期49卷 100-106页

作者：张兰陈标华王宁北京工业大学环境科学与工程学院北京100124

CO_(2)加氢制甲醇反应过程中产生的大量副产物水会加速催化剂中CuZn物种的聚集和烧结,导致催化剂严重失活。而CeO_(2)亲水性较弱,具有较高的水热稳定性,可以增强CuZn物种的分散。因此,通过水热合成法制备了一系列CeO_(2)载体晶面可调控... 详细信息

CO_(2)加氢制甲醇反应过程中产生的大量副产物水会加速催化剂中CuZn物种的聚集和烧结,导致催化剂严重失活。而CeO_(2)亲水性较弱,具有较高的水热稳定性,可以增强CuZn物种的分散。因此,通过水热合成法制备了一系列CeO_(2)载体晶面可调控的CuZn基催化剂,并在其中引入了适当浓度的氧空位。采用TEM、XRD和H_(2)-TPR等表征手段研究了合成的CeO_(2)载体及CuZn/CeO_(2)-y催化剂(y为rod、cube或otca)的形貌、结构和还原性能等物理化学性质,并考察了CuZn/CeO_(2)-y催化剂在CO_(2)加氢制甲醇反应中的催化性能。结果表明,暴露(110)晶面的纳米棒结构的CeO_(2)载体(CeO_(2)-rod)更有利于CuZn基物种的分散,并且CeO_(2)-rod与Cu物种形成了Cu—O—Ce界面,增强了催化剂同时吸附和活化CO_(2)和H_(2)的性能。因此,CuZn/CeO_(2)-rod表现出较高的CO_(2)转化率和甲醇选择性,在260℃、3MPa的条件下,甲醇时空收率为433.4g/(kg·h),甲醇选择性高达68.5%。同时,利用原位漫反射傅立叶变换红外光谱对CO_(2)加氢制甲醇的反应路径和重要中间物种的演变进行了详细研究,发现在CuZn/CeO_(2)催化剂的作用下,反应主要遵循甲酸盐路径,载体的晶面效应没有改变反应路径,但是提高了重要中间物种达到平衡的速率。

关键词： CuZn/CeO_(2)催化剂 CO_(2)加氢甲醇选择性氧空位

响应面模型用于Beta分子筛催化剂蜂窝状整体式成型的研究

在线全文

学校读者我要写书评

暂无评论

石油炼制与化工 2024年第6期55卷 83-91页

作者：韩莹莹王宁陈标华徐瑞年北京工业大学环境与生命学部北京100124

Beta分子筛由于具有独特的三维十二元环孔道结构,可提供更多活性组分附着位点,是在实际应用中具有优异性能的工业催化剂。在工业使用中,蜂窝整体式催化剂具有通量高、流场均匀、压降小、不易堵塞的优点,是气固或者液固催化反应的最优解... 详细信息

Beta分子筛由于具有独特的三维十二元环孔道结构,可提供更多活性组分附着位点,是在实际应用中具有优异性能的工业催化剂。在工业使用中,蜂窝整体式催化剂具有通量高、流场均匀、压降小、不易堵塞的优点,是气固或者液固催化反应的最优解决方案。但由于Beta分子筛吸水率高,收缩率大,导致蜂窝成型困难,严重限制了Beta分子筛的工业应用。基于此,选择拟薄水铝石(SB粉)为黏结剂、硝酸为胶溶剂、田菁粉为助挤剂,在水粉比为0.6的条件下制备一系列蜂窝整体式成型Beta分子筛催化剂,基于响应面法,评价了各原料的配比对蜂窝整体式催化剂机械强度的影响,得到了催化剂的机械强度与3个因素(黏结剂用量、胶溶剂用量、助挤剂用量)之间关系的二阶多项式近似模型函数。将试验结果与预测值进行对比,证明了预测模型的可靠性,并利用该模型找到最优的Beta分子筛蜂窝成型条件为SB粉质量分数36.1%、硝酸质量分数8.4%、田菁粉质量分数4.7%。

关键词： Beta分子筛蜂窝整体式催化剂响应面法

Fe改性分子筛催化剂CH_(4)选择性催化还原N_(2)O

在线全文

学校读者我要写书评

暂无评论

化工环保 2024年第3期44卷 398-404页

作者：温鹏刘宁陈标华代成娜北京工业大学环境科学与工程学院北京100124

针对N_(2)O的CH_(4)选择性催化还原(CH_(4)-SCR),采用浸渍法制备了系列Fe改性分子筛(BEA、ZSM-5、SSZ-13)催化剂。实验结果表明:2%Fe-BEA(负载量2%(w))具有较高的催化活性,在进气(N_(2)O 40%(φ,下同),CH_(4)10%,N250%)总流量为50 mL/min、反应器气时空速为12000 h^(–1)的条件下,250℃时的N_(2)O转化率达99.5%,CH_(4)转化率达94.6%;反应器连续运行20 h,N_(2)O转化率基本保持不变,CH_(4)转化率仅略有下降。表征结果显示,2%Fe-BEA较高的催化活性与其易形成大量离子态Fe^(3+)活性物种密切相关,而2%Fe-SSZ-13更易形成大量FeOx物种,故在3种分子筛催化剂中催化活性最低。2%Fe-BEA上N_(2)O的CH_(4)-SCR遵循自由基反应机理,形成羟基自由基和甲氧基自由基,并可经进一步氧化,通过甲酸盐路径生成CO_(2)和H2O。

关键词： N_(2)O CH_(4)选择性催化还原(CH_(4)-SCR) Fe-BEA分子筛反应机理

在线全文

学校读者我要写书评

暂无评论

N_(2)O氧化烷芳烃生产化学品技术进展

化工环保 2024年第3期44卷 353-361页

作者：陈亚春屈建海武蕊琦刘宁陈标华平顶山市普恩科技有限公司河南平顶山467013 北京工业大学环境科学与工程学院北京100124

N_(2)O作为一种温和的氧化剂,在烷芳烃氧化生产化学品领域具有巨大应用潜力。本文介绍了N_(2)O的来源和危害,分析了其作为氧化剂资源化利用生产更高价值化学品的优越性,总结了利用N_(2)O氧化甲烷制甲醇、氧化苯制苯酚、氧化丙烷制丙烯... 详细信息

N_(2)O作为一种温和的氧化剂,在烷芳烃氧化生产化学品领域具有巨大应用潜力。本文介绍了N_(2)O的来源和危害,分析了其作为氧化剂资源化利用生产更高价值化学品的优越性,总结了利用N_(2)O氧化甲烷制甲醇、氧化苯制苯酚、氧化丙烷制丙烯领域的最新研究进展,包括催化材料、反应机理、催化性能、催化剂失活等方面,并对该领域未来的研究方向进行了展望。

关键词： N_(2)O 烷烃芳烃氧化化学品生产

Globin-like mesoporous CeO2： A CO-assisted synthesis based on carbonate hydroxide precursors and its applications in low temperature CO oxidation

在线全文

学校读者我要写书评

暂无评论

Nano Research 2015年第4期8卷 1269-1278页

作者： Yeheng He Xin Liang biaohua chen Chemical Engineering College Beijing University of Chemical Technology Beijing 100029 China

Globin-like mesoporous CeO2 has been constructed by using a CO-assisted synthetic approach based on hydroxide carbonate precursors, in which CO plays a key role in the formation of the globin-like mesoporous precursors as the carbon source because of its preferential adsorption on Ce^3＋ under the hydrothermal conditions. The formation mechanism and the thermal transformation process from globin-like mesoporous CeCO3OH to CeO2 have been investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, BET surface area measurements, thermal analysis, Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy and X-ray photoelectron spec- troscopy. Rod-like building blocks interconnected by nanoparticles circle around to form each globin-like CeO2 spheres, leading to the formation of a mesoporous structure. The globin-like mesoporous CeO2 shows much better performance in CO catalytic oxidation than ordinary CeO2 nanoparticles obtained by directly calcining cerium nitrate. Moreover, the globin-like mesoporous CeO2 can act as an ideal matrix for supported catalysts. Metallic Au particles can be well dispersed in the globin-like CeO2 matrix to form Au/CeO2 supported catalysts, which exhibit excellent activity for CO oxidation at room temperature.

关键词： ceria CO-assisted synthesis mesoporous structure CO catalytic oxidation

Desulfurization of gasoline by condensation of thiophenes with formaldehyde in a biphasic system using aqueous phase of acids

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2017年第2期25卷 166-170页

作者： Miao He Yingxia Li Jie Zhang biaohua chen State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical Technology Beijing 100029 China

Aqueous phase of acids as catalysts for the desulfurization of gasoline by condensation of thiophenes with form- aldehyde in a biphasic system was investigated. Two types of model gasoline with and without aromatics and olefins were employed in this work. The desulfurization rates were above 90% on these two types of model gasoline using formic acid and HaPW12O40 （0.8 mol·L-1）, indicating that the presence of aromatics and olefins has no effect on the desulfurization rate. High temperature （above 90 ℃） was more favorable to the process for desulfurization. Four hours was considered to be the proper treating time for the sulfur removal. In addition, aqueous phase of acids could be recycled at least 4 times without decreasing desulfurization rate. Finally, the possible process for the integration of condensation desulfurization into the existing refinery process for the production of gasoline with low sulfur content was proposed.

关键词： Desulfurizafion Condensation AcidThiophene

Removal of hexavalent chromium in soil by lignin-based weakly acidic cation exchange resin

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2019年第10期27卷 2544-2550页

作者： Nawei chen Guo Qiu Chongpin Huang Li Liu Guangchao Li biaohua chen State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China

The adsorption of Cr(VI)from soil onto lignin-based weakly acidic cation exchange resin(LBR)has been *** is a three-dimensional amorphous polymer composed of methoxylated phenylpropane *** unique structure and chemical properties render the lignin suitable for the remediation of hexavalent chromium in the *** column leaching experiments were conducted to optimize the adsorption *** effects of contact time,p H,adsorbent dosage and temperature on the adsorption of Cr(VI)onto the LBR have been *** data were then correlated with Freundlich and Langmuir *** Langmuir isotherm model fits the experimental data better than the Freundlich *** was found that the LBR has a high adsorption capability for Cr(VI)(3.95 mg·g-1)with a removal rate of 91.9%.Thus,LBR can serve as a good absorbent for the reduction of the concentration of Cr(VI)in soil.

关键词： Lignin Cr(VI) Remediation Soil

Chlorine drying with hygroscopic ionic liquids

在线全文

学校读者我要写书评

暂无评论

Green Energy & Environment 2021年第3期6卷 350-362页

作者： Gangqiang Yu chengna Dai Bin Wu Ning Liu biaohua chen Ruinian Xu College of Environmental and Energy Engineering Beijing University of TechnologyBeijing100124China

The chlorine(Cl2)drying technology using ionic liquids(ILs)as absorbents was proposed for the first time and systematically investigated from the molecular level scaled up to the industrial *** hygroscopic IL[EMIM][CH3SO3]was screened as a suitable absorbent from 238 potential IL candidates consisting of 14 cations and 17 anions,by calculating the Cl2 and H2O solubility and separation selectivity of Cl2 to H2O in different ILs based on the COSMO-RS *** microscopic atomic and molecular insights into the separation mechanisms were deeply revealed by using COSMO-RS model analyses(i.e.,σ-profiles,σ-potentials,excess enthalpies,entropies,and Gibbs free energies)and quantum chemistry calculation(binding energies and weak interaction analyses).The Cl2 solubility in pure IL and H2O+IL systems were predicted by the COSMO-RS model,and the results agree with the microscopic mechanism ***,the strict equilibrium stage model employed with the COSMO-RS model parameters was built to perform the process simulation,and continuous Cl2 drying with ILs was conceptually designed and optimized at industrial *** was confirmed that[EMIM][CH3SO3]is a very promising absorbent leading to a less IL amount,a much lower energy consumption than the other IL[EMIM][BF4],which has a very bright industrialization potential used for Cl2 drying technology.

关键词： Ionic liquid Chlorine drying COSMO-RS model Quantum chemistry calculation Process design

Thermodynamic and kinetic roles of H2 in structure evolution of urchin-like Co:A density functional theory study

在线全文

学校读者我要写书评

暂无评论

Particuology 2020年第1期18卷 2-12页

作者： Xiaolei Wang Ning Liu Qinwei Zhang Xin Liang biaohua chen Donghai Mei State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China College of Environmental and Energy Engineering Beijing University of TechnologyBeijing 100124China Institute of Integrated Catalysis Pacific Northwest National LaboratoryRichlandWA 99352USA

Small gas molecules acting as good capping agents play important roles in controlling the morphologies and surface structures of metal *** the present work,the thermodynamic and kinetic roles of H2 molecules in the morphology of Co nanocrystals were systematically studied by density functional theory(DFT).The Gibbs surface free energies of Co(100),Co(110),and Co(111)at different hydrogen surface coverages were determined by ab initio *** phase diagram of stable H coverage on each plane was obtained and morphology evolution of the Co nanocrystals with various surface hydrogen coverages was predicted by the Wulff *** of H2 changes the facet stability,generating diverse morphological Co *** kinetic role of H2 in adatom Co surface diffusion at different H coverages was investigated by *** results suggest that surface H hinders Co surface diffusions,except for Co(100)at 0.56 monolayer *** projected density of states gives deeper insight into the electronic structures of Co adatoms with addition of the surface H atoms,which affect its surface diffusion ability.

关键词： Nanocrystal Co Surface free energy Surface diffusion Density functional theory