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Insights into Promoting Effect of Sm on Catalytic Performance of the CeO_(2)/Beta Catalyst in Direct Conversion of Bioethanol to Propylene

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Chemical Research in Chinese Universities 2022年第6期38卷 1547-1552页

作者： JIN Huan XU Ding TIAN Chao yue yinghong HUA Weiming GAO Zi Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Department of ChemistryFudan UniversityShanghai200438P.R.China Shanghai Customs Technology Center of Inspection and Test Shanghai200120P.R.China

A series of Sm-doped CeO_(2)/Beta composite catalysts with various Sm/Ce atomic ratios(0.1–0.4) were prepared by an incipient impregnation method, followed by calcination at 650 ℃. They were characterized by X-ray diffraction(XRD), N2 adsorption, X-ray photoelectron spectroscopy(XPS), Raman, NH3-temperature programmed desorption(TPD) and CO_(2)-TPD. The incorporation of Sm into CeO_(2)/Beta increases obviously the propylene yield for the selective conversion of ethanol to propylene. The promoting effect of Sm on CeO_(2)/Beta can be attributed to two reasons. One is more acetone intermediates are generated on the Sm-doped catalysts due to the enhanced formation of oxygen vacancies. The other is the conversion of acetone intermediate to propylene is enhanced owing to weaker and fewer acid sites on the Sm-doped catalysts.

关键词： Bioethanol Renewable propylene Sm-CeO_(2)/Beta composite Sm doping

Isobutane Dehydrogenation Assisted by C02 over Silicalite-i-Supported ZnO Catalysts: Influence of Support Crystallite Size

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Chinese Journal of Chemistry 2020年第7期38卷 703-708页

作者： Yajun Luo Chunling Wei Changxi Miao yinghong yue Weiming Hua Zi Gao Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Department of ChemistryFudan UniversityShanghai 200438China Shanghai Research Institute of Petrochemical Technology SINOPEC Shanghai 201208China

The ZnO catalysts supported on Silicalite-1 zeolites with different crystallite sizes(0.08,0.35,1 and 1.7 jjm,respectively)and 5%Zn were synthesized via an incipient wetness *** catalysts were characterized by XRD,N2 adsorption,SEM,TEM-EDX,DRIFT spectra and NH3-TPD,and their catalytic performance in isobutane dehydrogenation assisted by C02 was *** catalytic activity is strongly dependent on the crystallite size of Silicalite-1 *** ZnO/S-l-O.35 catalyst with ca.0.35 μmcrystallite size displays the highest activity,affording an initial isobutane conversion of 51.0%and 74.5%isobutene *** can be attributed to a higher amount of acid sites present on this catalyst as well as the largest amount of nest silanols possessed by the S-l-0.35 support.

关键词： method. crystallite catalyst

Liquid-phase a-Pinene Isomerization over Fe-doped Sulfated Zirconia Prepared by a Hydrothermal Treatment-assisted Process

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Chinese Journal of Chemistry 2011年第6期29卷 1095-1100页

作者： Liu, Jianfeng Zhao, Jie Miao, Changxi yue, yinghong Hua, Weiming Gao, Zi Shanghai Research Institute of Petrochemical Technology Shanghai 201208 China Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Department of Chemistry Fudan University Shanghai 200433 China

A series of Fe-doped （0.5%--3%） sulfated zirconia have been prepared by a hydrothermal treatment-assisted process. Textural and structural characterizations of the as-synthesized materials were performed by means of N2 adsorption, X-ray diffraction, transmission electron microscopy, scanning electron microscopy and thermogravimetric analysis. Temperature-programmed desorption of ammonia was used to determine the acidity of the samples. The effects of Fe-doping on the structure, acidity and catalytic activity of sulfated zirconia for liquid-phase a-pinene isornerization were investigated. The incorporation of small amounts of Fe into sulfated zirconia results in the increase of sulfate content and the number of acid sites, which is responsible for the enhanced activity of Fe-doped catalysts in comparison with the undoped one. Meanwhile, hydrothermal treatment helps to improve the activity of the catalyst.

关键词： sulfated zirconia Fe-doping hydrothermal treatment promoting effect acidity isomerization

Dehydrogenation of Isobutane to Isobutene with Carbon Dioxide over SBA-15-Supported Chromia-Ceria Catalysts

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Chinese Journal of Chemistry 2017年第10期35卷 1619-1626页

作者： Chunling Wei Fangqi Xue Changxi Miao yinghong yue Weimin Yang Weiming Hua Zi Gao Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Department of Chemistry Fudan University Shanghai 200433 China Shanghai Research Institute of Petrochemical Technology SINOPEC Shanghai 201208 China

A series of SBA-15-supported chromia-ceria catalysts with 3% Cr and 1%--5% Ce （3Cr-Ce/SBA） were pre- pared using an incipient wetness impregnation method. The catalysts were characterized by XRD, N2 adsorption, SEM, TEM-EDX, Raman spectroscopy, UV-vis spectroscopy, XPS and H2-TPR, and their catalytic performance for isobutane dehydrogenation with CO2 was tested. The addition of ceria to SBA-15-supported chromia improves the dispersion of chromium species. 3Cr-Ce/SBA catalysts are more active than SBA-15-supported chromia （3Cr/SBA）, which is due to a higher concentration of Cr^6＋ species present on the former catalysts. The 3Cr-3Ce/SBA catalyst shows the highest activity, which gives 35.4% isobutane conversion and 89.6% isobutene selectivity at 570℃ after 10 min of the reaction.

关键词： isobutane dehydrogenation carbon dioxide chromia-ceria SBA-15 supported catalyst

Oxidative Dehydrogenation of 1-Butene to 1,3-Butadiene Using CO2 over Cr-SiO2 Catalysts Prepared by Sol-gel Method

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Chemical Research in Chinese Universities 2018年第4期34卷 609-615页

作者： GAO Biao LUO Yajun MIAO Changxi yue yinghong YANG Weimin HUA Weiming GAO Zi Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Department of Chemistry Fudan University Shanghai 200433 P. R. China Shanghai Research Institute of PetrochemicaI Technology SINOPEC Shanghai 201208 P. R. China

A series of Cr-SiO2 catalysts with a Cr content（mass fraction） ranging from 0.5% to 9% was prepared by a sol-gel method. The catalysts were characterized by XRD, N2 adsorption, EDX elemental mapping, Raman spectros- copy, UV-Vis spectroscopy, XPS and H2-TPR, and their catalytic behavior in the dehydrogenation of 1-butene to 1,3-butadiene（BD） using CO2 as a soft oxidant was studied. The initial BD yield is well correlated with the amount of Cr6~ in the fresh catalysts. The highest BD yield of ca. 34% is achieved on the catalysts with 5%--9% Cr at 600 ~C -1 -1 and weight hourly space velocity（WHSV） of 4.5 g＇geat＇h ~ The promoting effect of CO2 on the BD yield was ob- served, which can be attributed to the reaction coupling between a simple dehydrogenation of 1-butene and the re- verse water-gas shift reaction as well as regaining the oxidation state（lattice oxygen） of reduced Cr3＋ species due to the mild oxidation ability of CO2. The Cr-SiO2 catalyst exhibits higher BD yield than the Cr catalyst supported on SBA-15, which is attributed to the higher amount of Cr6＋ present on the former catalyst.

关键词： 1,3-Butadiene CO2 oxidative dehydrogenation Cr-based catalyst Sol-gel method

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CO_2氧化低碳烷烃脱氢制低碳烯烃

石油化工 2010年第4期39卷 359-365页

作者：乐英红华伟明复旦大学化学系上海市分子催化和功能材料重点实验室上海200433

对近年来国内外关于CO2氧化低碳烷烃脱氢制低碳烯烃的研究成果进行了综述。CO2作为温和的氧化剂应用于低碳烷烃氧化脱氢可提高反应的平衡转化率,抑制催化剂失活,是一个有应用前景的新工艺。用于此类反应的催化体系主要有Cr系和Ga系,但... 详细信息

对近年来国内外关于CO2氧化低碳烷烃脱氢制低碳烯烃的研究成果进行了综述。CO2作为温和的氧化剂应用于低碳烷烃氧化脱氢可提高反应的平衡转化率,抑制催化剂失活,是一个有应用前景的新工艺。用于此类反应的催化体系主要有Cr系和Ga系,但这两类催化剂的稳定性较差,通过调变催化剂载体表面的性质来改变活性组分与载体间的相互作用,可以提高催化剂的稳定性。不同催化体系中CO2的作用机制不同,Cr系催化剂上主要为氧化还原机理,而Ga系催化剂上则为异裂机理。为进一步提高反应效率,探索和研究同时具有脱氢与活化CO2能力的新催化体系是发展方向。

关键词：低碳烷烃氧化脱氢低碳烯烃二氧化碳铬系催化剂镓系催化剂

碱催化剂g-C3N4在液相反应中溶胀特性的研究

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物理化学学报 2020年第1期36卷 227-233页

作者：吴结群华伟明乐英红高滋复旦大学化学系上海市分子催化和功能材料重点实验室上海200438

通过三聚氰胺、双腈胺、硫脲或尿素的高温热解制备了四种比表面不同的石墨型碳化氮材料(g-C3N4),利用X射线衍射(XRD)、扫描电子显微镜(SEM)、傅里叶变换红外光谱(FTIR)、X射线光电子能谱(XPS)、热重分析(TGA)和N2吸附方法对所得材料进... 详细信息

通过三聚氰胺、双腈胺、硫脲或尿素的高温热解制备了四种比表面不同的石墨型碳化氮材料(g-C3N4),利用X射线衍射(XRD)、扫描电子显微镜(SEM)、傅里叶变换红外光谱(FTIR)、X射线光电子能谱(XPS)、热重分析(TGA)和N2吸附方法对所得材料进行结构与表面性质的表征,用CO2程序升温脱附(CO2-TPD)和酸碱滴定方法测试了其碱性。考察了这些材料对于不同溶剂中苯甲醛与丙二腈Knoevenagel缩合反应的催化活性。g-C3N4在弱极性溶剂甲苯中的催化活性很低,且活性大小与其比表面和表面碱性密切相关,而在极性溶剂乙醇中四种g-C3N4的催化活性则相差不大,且都远高于甲苯中的活性。上述结果无法用常规的碱性表征数据来解释。进一步的实验证明在极性溶剂中g-C3N4会发生溶胀,使得表面暴露更多的碱性位,因而催化活性大大提高。不同溶剂中的反应结果表明g-C3N4的溶胀效应随反应溶剂的极性增加而增强。重复利用实验表明gC3N4在液相反应中具有良好的稳定性,其对于苯甲醛的转化率在重复利用三次后由74.2%下降至63.8%。

关键词： g-C3N4 碱催化 Knoevenagel缩合溶胀效应

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全氟磺酸功能化碳纳米管的制备及其催化性能

催化学报 2014年第11期35卷 1874-1882页

作者：张梦晓李璀灿华伟明乐英红高滋复旦大学化学系上海市分子催化和功能材料重点实验室上海200433

采用全氟磺酸-全氟乙烯共聚物的液相沉积方法制备了全氟磺酸功能化碳纳米管催化剂,利用N2吸附、扫描电子显微镜、透射电子显微镜、傅里叶变换红外光谱以及酸碱滴定等方法对材料的结构和酸性进行了表征,考察了温度和溶剂对催化剂稳定性... 详细信息

采用全氟磺酸-全氟乙烯共聚物的液相沉积方法制备了全氟磺酸功能化碳纳米管催化剂,利用N2吸附、扫描电子显微镜、透射电子显微镜、傅里叶变换红外光谱以及酸碱滴定等方法对材料的结构和酸性进行了表征,考察了温度和溶剂对催化剂稳定性的影响.结果表明,催化剂在极性和非极性溶液中均十分稳定,并且具有良好的热稳定性,使用温度可达300°C.该催化剂在对苯二酚与叔丁醇的烷基化反应中表现出优异的催化性能,其催化活性与稳定性均高于聚苯乙烯磺酸功能化的碳纳米管催化剂.

关键词：碳纳米管全氟磺酸酸性稳定性对苯二酚叔丁醇烷基化反应

亚微米ZSM-5负载Cr催化剂上乙烷CO_2气氛下脱氢制乙烯（英文）

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催化学报 2015年第8期36卷 1242-1248页

作者：程彦虎张帆张翼缪长喜华伟明乐英红高滋复旦大学化学系上海市分子催化与功能材料重点实验室上海200433 中石化上海石油化工研究院上海201208

石油资源的日趋短缺使天然气和页岩气的开发利用受到重视,因而低碳烷烃脱氢制取低碳烯烃也随之引起了人们越来越多的关注.由于乙烷纯脱氢反应的平衡收率低,能耗高,而氧气氧化脱氢又易将乙烷深度氧化为CO2或CO,因此开发具有反应条件温和... 详细信息

石油资源的日趋短缺使天然气和页岩气的开发利用受到重视,因而低碳烷烃脱氢制取低碳烯烃也随之引起了人们越来越多的关注.由于乙烷纯脱氢反应的平衡收率低,能耗高,而氧气氧化脱氢又易将乙烷深度氧化为CO2或CO,因此开发具有反应条件温和、装置投资和操作费用低等优势的CO2气氛下乙烷脱氢的技术路线日益得到重视.CrOx是该反应理想的催化剂之一,CO2的加入可使CrOx对乙烷脱氢的催化活性提升3倍,然而受困于CrOx过小的比表面积,通常将CrOx制备成负载型催化剂使用.CrOx的常见载体有Al2O3,Zr O2和Si O2等氧化物及MCM-41,SBA-15,SBA-1和MSU-x等介孔硅材料,ZSM-5作为载体负载CrOx用于低碳烷烃脱氢的研究则较少,所得结果也不甚理想.我们采用亚微米尺寸的ZSM-5作为载体制备了负载型Cr O x催化剂,研究了其在CO2气氛下催化乙烷脱氢反应,发现该催化剂具有非常优异的脱氢活性,高硅铝比和Na型的ZSM-5作载体对反应更加有利,而且在反应进行50 h后,催化剂依然保持很好的活性和很高的乙烯收率,这是在一般负载型CrOx催化剂上所不能实现的.X射线光电子能谱(XPS)表征发现,Na型ZSM-5载体制得的催化剂具有更高的Cr6+/Cr3+比.一般认为,Cr6+是Cr系催化剂进行低碳烷烃脱氢反应时的活性位(或活性位前驱体),因此可以初步判定,Na型载体具有很好催化效果的原因可能是由它制得的催化剂具有更多的反应活性位.程序升温还原(H2-TPR)表征结果证实了这一点,Na型载体明显具有更高的H2消耗量;也就是说,Na型载体制得的催化剂具有更多的可还原Cr物种,即脱氢活性位.进一步表征发现,反应活性还与Cr物种存在形式有关.文献报道,低聚态的Cr物种和孤立态的Cr物种比Cr2O3有更好的催化活性.通过漫反射紫外-可见光谱(UV-Vis)对Cr物种的存在形态进行表征后发现,Na型载体上Cr主要以四配位形式存在,而在H型载体上出现了对应于六配位的Cr物种;激光Raman表征结果表明,Na型载体上出现的都是低聚态Cr物种和孤立态Cr物种,而H型载体上出现了明显的对应于α-Cr2O3的峰,说明相较于H型载体,Na型载体更有利于Cr组分分散,这也是Na型ZSM-5载体催化剂具有更高活性的原因之一.CO2引入后对乙烷脱氢反应具有明显的促进作用,特别是在CO2/C2H6=5时,催化剂上C2H6转化率是非CO2气氛下的3.2倍;同时,CO2的引入也提高了脱氢反应的稳定性.在非CO2气氛下,反应进行6 h后,C2H6转化率降低到初活性的60%左右,而在CO2/C2H6=5时,相同时间内催化剂活性下降仅有5%左右.实验分析了CO2对脱氢反应具有促进作用的原因.在脱氢反应温度650o C下,CO2/H2=1时进行了逆水煤气反应测试,发现CO2的转化率达到22.5%,说明引入CO2后可以通过逆水煤气反应有效地消耗掉乙烷脱氢反应生成的H2,从而促进反应向脱氢方向进行;CO2的引入也可以促进Cr物种的CrOx/CrOx-1循环,从而提高催化剂效率,减缓催化剂失活;CO2还可与反应中生成的积碳类物质发生Boudouard反应,将反应活性位暴露出来,从而提高催化剂的稳定性.CO2气氛下反应6 h后催化剂的积碳量为3.0%,低于非CO2气氛下的3.4%,同时在脱氢反应中生成的CO量与消耗掉的CO2量的比值约为1.4,也有力地说明Boudouard反应的存在.

关键词：脱氢反应乙烷 ZSM-5分子筛亚微米二氧化碳