搜索结果: 91-105 共查到“知识库 催化反应工程”相关记录895条 . 查询时间(1.311 秒)
In situ generation of trityl carbocation (Ph3C+) as a homogeneous organocatalyst for the efficient synthesis of 4, 4’-(arylmethylene)-bis(3-methyl-1-phenyl-1H-pyrazol-5-ol)s
Trityl chloride (Ph3CCl) Trityl carbocation (Ph3C+) 4,4'-(Arylmethylene)-bis(3- methyl-1-phenyl-1H-pyrazol-5-ol) 3-Methyl-1-phenyl-1H-pyrazol-5(4H)-one Solvent-free synthesis
2014/3/11
Trityl chloride (Ph3CCl) efficiently catalyzes the condensation of 3-methyl-1-phenyl-1H-pyrazol- 5(4H)-one and aromatic aldehydes under mild and solvent-free conditions, affording 4,4'- (arylmethylene...
H3PW12O40 catalyzed synthesis of benzoxazine and quinazoline in aqueous media
Heteropoly acid 1,3-Benzoxazine-4-one 2-Substituted-quinazolin-4(3H)-one 2-Substituted-2,3-dihydroquinazolin-4(1H)-one
2014/3/11
A heteropolyacid efficiently catalyzed the cyclocondensation reaction of 2-aminobenzamide and salicylamide with aldehydes and ketones to afford good yields of benzoxazine and quinazoline ring systems ...
Poly(4-vinylpyridinium)hydrogen sulfate: A novel and efficient catalyst for the synthesis of 13-aryl-indeno[1, 2-b]naphtha[1, 2-e]pyran-12(13H)-ones under solvent-free conditions
Poly(4-vinylpyridinium)hydrogen sulfate Indenonaphthopyrans, H-indene-1,3-dione β-Naphthol
2014/3/11
An facile and efficient protocol for the synthesis of 13-aryl-indeno[1,2-b]naphtha[1,2-e]pyran- 12(13H)- ones has been developed that proceeds via the one-pot three-component sequential reaction of an...
固-溶法制备中温固体氧化物燃料电池高性能La0.8Sr0.2MnO3-Ba0.5Sr0.5Co0.8Fe0.2O3阴极
固体氧化物燃料电池 中温 La0.8Sr0.2MnO3-Ba0.5Sr0.5Co0.8Fe0.2O3复合阴极 极化电阻 性能稳定性
2014/3/11
研究了新型固溶法合成La0.8Sr0.2MnO3（LSM）包覆Ba0.5Sr0.5Co0.8Fe0.2O3（BSCF）复合粉体（LSM-BSCF），并探讨了其作为中温固体氧化物燃料电池阴极材料的电化学性能。LSM-BSCF阴极结合了LSM和BSCF阴极的优点，不仅增大了三相界面，而且稳定了微观结构。当温度为600-750℃时，其极化阻抗为0.61-0.09 Ω·cm2。与溶液注入法制备的高性能电极...
采用自旋极化密度泛函理论和周期平板模型，对C2H4在铁基费托合成催化剂活性相之一Fe3C（100）表面从热力学和动力学两个方面分析了C2H4在Fe3C（100）表面进行脱氢和裂解反应的竞争性。结果表明，C2H4在Fe3C（100）表面的μ-bridging吸附比π、di-σ吸附更加稳定；C2H4与Fe3C（100）面的相互作用导致C2H4的C原子部分发生重新杂化（sp2→sp3），使C原子呈近四面...
Polyvinyl amine coated Fe3O4@SiO2 magnetic microspheres for Knoevenagel condensation
Basic magnetic catalyst Fe3O4 nanoparticle Polyvinyl amine Knoevenagel condensation
2014/3/11
Polyvinyl amine coated Fe3O4@SiO2 composite microspheres with a core-shell structure were prepared and employed as a magnetic catalyst for Knoevenagel condensation under mild conditions. The catalyst ...
Wet air oxidation for the decolorization of dye wastewater: An overview of the last two decades
Wet air oxidation Dye wastewater Decolorization Sustainability
2014/3/11
Wet air oxidation (WAO), a liquid phase reaction between organic materials in water and oxygen, is one of the most economical and technologically viable advanced oxidation processes for wastewater tre...
Silica-bonded N-propylpiperazine sodium n-propionate as recyclable catalyst for synthesis of 4H-pyran derivatives（图）
Silica-bonded n-propylpiperazine sodium n-propionate Heterogeneous solid base catalyst Aldehyde
2013/12/5
Silica-bonded N-propylpiperazine sodium n-propionate (SBPPSP) was found to act as an efficient solid base for the preparation of a series of 4H-benzo[b]pyran derivatives. SBPPSP was used as a recyclab...
Aldol condensations of a variety of different aldehydes and ketones under ultrasonic irradiation using poly(N-vinylimidazole) as a new heterogeneous base catalyst under solvent-free conditions in a liquid-solid system Nader Ghaffari Khaligha, Taraneh Mihankhahb（图）
Ultrasound-assisted reaction Liquid-solid system Poly(N-vinylimidazole) Aldol condensation, Solvent-free
2013/12/5
An ultrasound-assisted aldol condensation reaction has been developed for a range of ketones with a variety of aromatic aldehydes using poly(N-vinylimidazole) as a solid base catalyst in a liquid-soli...
研究了酸性助剂对TiO2纳米管(TNT)负载的V2O5催化剂(V2O5/TNT)性能的影响, 发现经硫酸、磷酸或磷钨酸处理后,TNT的结构稳定, 但表面酸性和氧化-还原性发生了变化,从而改变了甲醇选择氧化为甲缩醛的催化性能.实验结果表明,V2O5/TNT催化剂经硫酸修饰和673 K焙烧,其甲缩醛选择性显著提高,且维持了较高的甲醇转化率.催化剂表征表明,高温焙烧促进了硫酸根与钒物种之间的强相互作用,...
以乙酰丙酮钯作为催化剂前体,异丙醇作为氢源,在碱性的反应过程中原位得到纳米尺度的钯纳米颗粒,并进一步得到钯-氢活性结构, 实现硝基的还原及氮氮键的偶联.该催化体系还可以实现C=C和C=O键的有效还原.这类原位得到的钯纳米催化材料表面裸露, 因而具有更高的催化活性.
以甲酸作为氢源,采用铜基复合金属氧化物催化剂,催化氢解甘油制备1,2-丙二醇,其中液相甲酸的高选择性分解是实现甘油氢解的必要和关键步骤.活性测试表明,高分散的铜和ZrO2载体间的协同作用对甲酸分解和甘油到1,2-丙二醇的转化至关重要,20%Cu/ZrO2催化剂的活性最佳.由于避免使用相对昂贵的化石燃料氢,因而该催化体系在生物质的高值利用方面具有潜在的应用前景.
采用商业WO3和Raney Ni为组合催化剂,以菊芋秸秆为反应原料制备了乙二醇. 菊芋秸秆中含纤维素51.6 wt%、半纤维素10.3 wt%、木质素17.2 wt%、灰分1.7 wt%和水溶性物质19.2 wt%.木质素对纤维素和半纤维素的转化影响较小,而水溶性物质的存在抑制了乙二醇的生成,因此由未经过预处理的菊芋秸秆得到的乙二醇收率只有29.9%.而经简单的热水预处理可除掉其中的大部分水溶物,...
Pt-表层限域的表面FeOx结构用于低温CO氧化反应（图）
一氧化碳氧化 铂-表层 铁氧化物 界面催化
2013/12/6
通过简单的浸渍-还原并随后在酸性溶液中处理制备了Pt-Cu双金属催化剂.利用电感耦合等离子体发射光谱、X射线衍射和X射线光电子能谱对不同处理条件下的Pt-Cu纳米粒子的结构和组成进行了表征.研究发现,Pt-Cu催化剂在高温H2中还原形成了PtCu3合金结构,酸洗处理后形成了包含Pt-骨架(Pt-skeleton)的表面结构和PtCu3合金核的纳米粒子.而Pt-骨架结构又可通过在H2中退火转变为规整...
