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Anti-carbon deposition performance of twinned HZSM-5 encapsulated Ru in the toluene alkylation with methanol

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Chinese Journal of Chemical Engineering 2023年第9期61卷 1-8页

作者： Guixian Li Tao Tian Hanxu Li Jinlian Li tingna shao Qi Zhang Peng Dong School of Petrochemical Engineering Lanzhou University of TechnologyLanzhou 730050China Key Laboratory of Low Carbon Energy and Chemical Engineering of Gansu Province Lanzhou 730050China

Toluene methylation with methanol to produce para-xylene has been extensively and intensively ***,the methanol-to-hydrocarbons(MTH)side reaction in this reaction is difficult to be inhibited,which will cause a mass of carbon deposition and cover the catalyst surface,resulting in catalyst ***,a dual-functional Ru@HZSM-5 catalyst with high para-selectivity and low carbon deposition was prepared by encapsulating Ru metal with *** to catalytic performance studies,the Ru@HZSM-5 catalyst produced xylene selectivity of 98%and para-xylene selectivity of 96%.Meanwhile,we find that carbon precursors(***)were very little when Ru catalyst was used,but the results of HZSM-5 catalyst were completely ***@HZSM-5 catalyst achieves a lower carbon deposition rate of only 6%of *** main possible reason for this is that the initial C-C bond between methanol and the olefin is difficult to form.

关键词： Twinned HZSM-5 Encapsulated metal Shape-selective catalysis Anti-carbon deposition

Sign reversal of anisotropic magnetoresistance and anomalous thickness-dependent resistivity in Sr_(2)CrWO_(6)/SrTiO_(3) films

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Chinese Physics B 2022年第10期31卷 146-152页

作者： Chunli Yao tingna shao Mingrui Liu Zitao Zhang Weimin Jiang Qiang Zhao Yujie Qiao Meihui Chen Xingyu Chen Ruifen Dou Changmin Xiong Jiacai Nie Department of Physics Beijing Normal UniversityBeijing 100875China State Key Laboratory of Luminescence and Applications Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China

High-quality Sr_(2)CrWO_(6)(SCWO) films have been grown on SrTiO_(3)(STO) substrate by pulsed laser deposition under low oxygen pressure. With decrease of the film thickness, a drastic conductivity increase is observed. The Hall measurements show that the thicker the film, the lower the carrier density. An extrinsic mechanism of charge doping due to the dominance of oxygen vacancies at SCWO/STO interfaces is proposed. The distribution and gradient of carrier concentration in SCWO films are considered to be related to this phenomenon. Resistivity behavior observed in these films is found to follow the variable range hopping model. It is revealed that with increase of the film thickness, the extent of disorder in the lattice increases, which gives a clear evidence of disorder-induced localization charge carriers in these *** measurements show that there is a negative magnetoresistance in SCWO films, which is considered to be caused by the magnetic scattering of magnetic elements Cr^(3+) and W^(5+). In addition, a sign reversal of anisotropic magnetoresistance(AMR) in SCWO film is observed for the first time, when the temperature varies across a characteristic value, T_(M). Magnetization-temperature measurements demonstrate that this AMR sign reversal is caused by the direction transition of easy axis of magnetization from the in-plane ferromagnetic order at T > T_(M) to the out-of-plane at T < T_(M).

关键词： Sr_(2)CrWO_(6)/SrTiO_(3) anisotropic magnetoresistance sign reversal resistivity

VO_(x)/AlPO_(4)催化剂合成及其催化苯羟基化反应性能

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精细化工 2023年第4期40卷 861-868页

作者：李贵贤李晗旭田涛李金莲邵婷娜董鹏兰州理工大学石油化工学院甘肃兰州730050

以异丙醇铝与磷酸为原料,离子液体1-丁基-3-甲基咪唑溴盐([Bmim]Br)与二正丙胺为共模板剂合成了Al PO_(4),进而采用水热法将V_(2)O_(5)负载于Al PO_(4)载体制备了VO_(x)/Al PO_(4)催化剂。采用XRD、SEM、TEM、Mapping、FTIR、N_(2)吸附... 详细信息

以异丙醇铝与磷酸为原料,离子液体1-丁基-3-甲基咪唑溴盐([Bmim]Br)与二正丙胺为共模板剂合成了Al PO_(4),进而采用水热法将V_(2)O_(5)负载于Al PO_(4)载体制备了VO_(x)/Al PO_(4)催化剂。采用XRD、SEM、TEM、Mapping、FTIR、N_(2)吸附-脱附、XPS对催化剂进行了表征,考察了其在苯羟基化反应中的催化性能。结果表明,钒氧化物负载量为16%(以V_(2)O_(5)和Al PO_(4)的总质量为基准,下同)的催化剂具有最多且分布均匀的V4+活性中心、契合反应的酸性微环境,在催化剂用量为0.2 g,苯用量4 mL,质量分数30%的H2O2用量12.5 mL,乙腈用量15 mL,反应温度70℃,反应时间7 h的条件下,苯转化率为53.4%,苯酚选择性为98.4%。基于催化剂表征分析及性能评估,推测催化反应机理是以亲核氧化机理为主,自由基机理为辅。

关键词： VO_(x)/Al PO_(4) 苯苯酚羟化自由基催化技术

Anti-carbon deposition performance of twinned HZSM-5 encapsulated Ru in the toluene alkylation with methanol

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Doping-enhanced robustness of anomaly-related magnetoresistance in WTe_(2±α)flakes

中国化学工程学报（英文版） 2023年第9期

作者： Guixian Li Tao Tian Hanxu Li Jinlian Li tingna shao Qi Zhang Peng Dong

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Chinese Physics B 2023年第4期32卷 634-638页

作者：孟建超陈鑫祥邵婷娜刘明睿姜伟民张子涛熊昌民窦瑞芬聂家财 Department of Physics Beijing Normal UniversityBeijing 100875China College of Science Inner Mongolia University of TechnologyHohhot 010051China State Key Laboratory of Luminescence and Applications Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China

We study systematically the negative magnetoresistance(MR)effect in WTe_(2±α)flakes with different thicknesses and doping *** negative MR is sensitive to the relative orientation between electrical-/magnetic-field and crystallographic orientation of WTe_(2±α).The analysis proves that the negative MR originates from chiral anomaly and is *** entropy mobility spectrum is used to analyze the electron and hole concentrations in the flake *** is found that the negative MR observed in WTe_(2±α)flakes with low doping concentration is small,and the high doping concentration is *** doping-induced disorder obviously inhibits the positive MR,so the negative MR can be more easily *** a word,we introduce disorder to suppress positive MR by doping,and successfully obtain the negative MR in WTe_(2±α)flakes with different thicknesses and doping concentrations,which indicates that the chiral anomaly effect in WTe_(2)is robust.

关键词： Weyl semimetal WTe_(2±α)flakes doping chiral anomaly robustness