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41.
Zhaoqing Li Zhufeng Liu Xiao Yang Annan Chen Peng Chen Lei Yang Chunze Yan Yusheng Shi 《Materials》2022,15(9)
In this study, in situ TiO2 was grown on the surface of graphene by a facile sol–gel method to form black TiO2/graphene composites with highly improved photocatalytic activity. The combination of graphene and TiO2 was beneficial to eliminate the recombination of photogenerated electron holes. The self-doping Ti3+ was introduced, accompanied by the crystallization of amorphous TiO2, during the hydrogenation process. Consequently, the narrowed bandgap caused by self-doping Ti3+ enhanced the visible light absorption and thus made the composites appear black. Both of them improved the photocatalytic performance of the synthesized black TiO2/graphene composites. The band structure of the composite was analyzed by valence band XPS, revealing the reason for the high visible light catalytic performance of the composite. The results proved that the black TiO2/graphene composites synthesized show attractive potential for applications in environmental and energy issues. 相似文献
42.
Herein, the impact of cerium species loaded on mesoporous silica of MCF type on the state and catalytic activity of ruthenium species was studied. Up to 20 wt.% of cerium was incorporated on the silica surface, whereas the same 1 wt.% of Ru loading was applied. The samples prepared were examined by low temperature N2 adsorption/desorption, XRD, XRF, ICP-OES, XPS and H2 chemisorption. The catalytic activity of the materials obtained was investigated in the transformation of levulinic acid to γ-valerolactone. It was documented that the presence of Ce favored an increase in the dispersion of ruthenium species, which had a positive impact on the hydrogenation activity for up to 10 wt.% of Ce. Nevertheless, the highest cerium loading had a negative influence on the textural parameters of the support. 相似文献
43.
以Raney镍为催化剂,在淤浆鼓泡床中进行丁炔二醇加氢合成丁二醇这一两步串联加氢反应。探讨了在实验条件下气液传质、液-固传质和颗粒表面反应的相对阻力,从而用定量对比法确证反应属动力学控制。其本征速率方程可用幂函数或Langmuir-Hinshelwood模型表达。前者适用于宏观过程对比;后者适用于本征机理研究,并可对液相反应物级数的变化作出满意的解释。 相似文献
44.
经热力学分析得出:当压力在3.0 ̄4.0MPa,温度在180 ̄300℃的范围内,CO2加氢生成乙醛在热力学上是可能的。实验表明,在Rh-Ag/SiO2、Rh-Ag-LiCl/SiO2催化剂上有乙醛生成,乙醛的选择性最高可达45.89%。 相似文献
45.
应用微型催化反应-色谱装置,在总压1~2MPa、温度473~573K、氢油体积比500、质量空速1~30h ̄(-1)的范围内,研究了噻吩在Mo-Ni-Co/Al_2O_3催化剂上的加氢脱硫动力学。根据加氢脱硫反应具有极限转化率的特点;用类二级反应的数学模型描述噻吩脱硫的动力学行为,求得活化能为76.21kJ/mol,频率因子为3.67×108。 相似文献
46.
用两种间隙式小型高压釜,在不同条件下考察了究州煤的加氢液化性能,並与联邦德国加氢原料煤Wester holt煤和美国的Illinois 6号煤进行了对比。试验结果表明:兖州煤具有较高的加氢反应活性,它略高于后一种煤,明显高于前一种煤。以循环油为溶剂,拜尔赤泥为催化剂,在氢初压9MPa,435℃和60min条件下,兖州煤的转化率达84%:油产率为46%。 相似文献
47.
48.
YOSHIHIDE HASHIMOTO HARUHIKO AOYAGI MICHINORI WAKI TETSUO KATO NOBUO IZUMIYA 《Chemical biology & drug design》1983,21(1):11-15
Four cyclic dehydrodipeptides, cyclo (-Δaminoacyl-L-Ala-), in which aminoacyl is Phe, Apb (2-amino-4-phenylbutanoic acid), App (2-amino-5-phenylpentanoic acid) and Aph (2-amino-6-phenylhexanoic acid), were prepared by condensation of cyclo (-N-Ac-Gly-N-Ac-L-Ala-) with the corresponding aldehydes. Among them, the yield of cyclo (-ΔApb-L-Ala-) was exceptionally low. Each compound was hydrogenated in the presence of Pd black at various temperatures and chiral induction in hydrogenation was evaluated. Low chiral induction at high temperature (50d?) was observed in the case of cyclo (-ΔPhe-L-Ala-). Optically pure L-Apb, L-App and L-Aph were obtained from the corresponding cyclic dehydrodipeptides, respectively, by hydrogenation and subsequent acid hydrolysis. 相似文献
49.
A modified method is reported for the prepartion of Nα-9-fluorenylmethyloxycarbonyl-Nδ,ω bis-adamantyloxycarbonyl-L-arginine, giving an overall yield of 60% over three steps based on Nα-benzyloxycarbonyl-L-arginine. Commercially available adamantyl fluoroformate for guanidine function protection of Nα benzyloxycarbonyl-L-arginine, catalytic transfer hydrogenation with formic acid on palladium black for removal of the benzyloxycarbonyl protecting group, and fluorenylmethylsuccinimidyl carbonate for the final synthesis, were introduced to simplify and reduce the cost of preparation of this arginine derivative. The reaction conditions have been accurately studied at each step in order to optimize the yields. 相似文献
50.
[目的]鉴别、分析与评价工程项目可能产生的职业病危害因素和危害程度及危害类别,确定工程项目在职业病防治方面的可行性,为工程项目的设计提供必要的职业病危害防护对策和建议。[方法]根据柴油加氢精制装置生产过程中可能产生的职业病危害因素的特点,采用类比和定量分级相结合进行评价。[结果]装置使用的物料、介质及生产过程中存在毒物、粉尘、噪声、高温等职业病危害因素,其中含有高毒物质硫化氢,其危害程度高,系统内存量大、涉及范围广,是该装置最主要的职业病危害因素。[结论]在本工程项目可行性研究过程中,遵循了国家有关工程项目职业病危害防护的法律、法规,建议采用的职业卫生防护措施较为可行。从职业病防治角度分析,本工程项目的建设是可行的。 相似文献