浸渍溶剂对Pt/炭-氧化铝催化氢化2-氧-4-苯基丁酸乙酯的影响

螯合辅助溶剂挥发共组装法制备的炭-氧化铝复合材料为载体,分别使用水、乙醇或二者混合物为氯铂酸的分散介质,浸渍制备炭-氧化铝复合材料负载Pt催化剂.通过XRD,N2物理吸附以及TEM表征可知,乙醇作为浸渍溶剂时,最有利于Pt的分散,而混合溶剂浸渍制备的催化剂Pt颗粒最大.2-氧-4-苯基丁酸乙酯不对称加氢反应结果表明,氯铂酸水溶液浸渍得到的催化剂Pt纳米粒子的粒径有利于获得高的光学选择性,催化剂经辛可尼丁修饰后,以乙酸为反应溶剂,可获得最高84.8%的光学选择性.此外,该催化剂重复利用性能优异,可以重复利用22次,活性没有下降.     

PW_(11)O_(39)Co(Ⅱ)(H_2O)~(5-)的均相及异相体系可见光催化性能研究

以模型污染物罗丹明B(RhB)的光降解为探针,评估了Keggin型钴取代杂多阴离子PW11O39Co髤(H2O)5-(PW11Co)及其异相体系PW11Co/D301R的可见光催化活性,提出了光催化反应的机理,同时考察了催化剂用量、溶液酸度以及溶液中PW11Co和RhB的相互作用对RhB可见光催化降解速率的影响。实验结果表明,PW11Co均相体系及其异相体系PW11Co/D301R对RhB的可见光降解均有较高的光催化活性,但PW11Co/D301R的光催化活性更高。导致RhB降解的主要是羟基自由基。与PW11Co均相体系相比,在PW11Co/D301R异相体系中由于PW11Co与RhB的配位作用大为减弱,同时D301R对RhB具有富集作用,因而大大提高了RhB的光催化降解速率。     

大孔Mo-Ni/Al_2O_3催化剂的催化裂化柴油加氢性能研究

采用三次纳米自组装合成法,制备了一种以二次纳米自组装Al2O3为主体的大孔主客体催化剂FA-40,具有0.78 cm3·g-1的孔容、114 m2·g-1的比表面积、27 nm的平均孔径、6.0 nm和40 nm的双峰孔结构、孔分布在10~100 nm高度集中、低堆积密度为0.56 g·cm-3、活性金属含量高达35.70%。XRD和TEM分析结果显示,活性金属以直径小于2 nm的微晶态纳米粒子形式均匀分散于主体表面。采用劣质催化裂化柴油进行20 h加氢实验评价,反应趋于稳定时,FA-40的脱硫、脱氮及芳烃饱和率分别达到94.4%、95.5%和67.9%,与F-5相比分别提高了20%、80%和140%。300 h的长周期加氢实验表明,FA-40具有良好的加氢性能。     

中国化学会第17届反应性高分子学术讨论会征文启事

正经中国化学会批准,中国化学会第17届反应性高分子学术讨论会定于2014年7月18~21日在常州大学召开,欢迎您报名参加,并欢迎您就下列内容踊跃投稿:1.离子交换材料、吸附材料、高分子催化剂、高分子试剂2.生物医用高分子材料3.新型反应性高分子(如高分子膜、纤维等分离材料)4.反应性高分子的合成、应用及表征论文摘要要求具有创新性、指导性,凡已在国内外学术会议上报     

N-Protection of amines using pyridinium 2, 2, 2-trifluoroacetate ionic liquid as an efficient and reusable catalyst

A simple, green, and efficient method for the N-tert-butoxycarbonylation of amines by pyridinium 2,2,2- trifluoroacetate （[Py][OTf]） as an efficient and reusable catalyst is reported. In general, electron donating groups on aryl group give rise to the higher yields than electron withdrawing groups. Clean reaction, short reaction times, high yields, reusability of catalyst, and easy preparation of it are some advantages of this work.     

Propane-1,2,3-triyl tris(hydrogen sulfate): A mild and effcient recyclable catalyst for the synthesis of biscoumarin derivatives in water and solvent-free conditions简

A simple, efficient, and ecofriendly procedure has been developed using propane-l,2,3-triyl tris（hydrogen sulfate） as a catalyst for the synthesis of biscoumarin derivatives in water and solvent-free conditions. The significant features of the present protocol are simplicity, environmentally benign, high yields, no chromatographic separation, and recyclability of the catalyst.     

The promoting role of minor amount of water in solvent-free hydrogenation of halogenated nitrobenzenes

This study shows that minor amount of water plays a very important role in solvent-free hydrogenation of halogenated nitrobenzenes. For dried sponge Pd, the reaction cannot occur in the absence of water. For Pd/C catalyst, minor amount of water reduces the induction time, increases the reaction rate and reaction TOFs. Water might enhance the diffusion, adsorption and dissociation of H2 on Pd catalysts.     

Ceric ammonium nitrate supported HY-zeolite：An efficient catalyst for the synthesis of 1, 8-dioxo-octahydroxanthenes

Ceric ammonium nitrate （CAN） supported HY-zeolite has been used as an efficient catalyst for the one- pot synthesis of 1,8-dioxo-octahydroxanthenes from the readily available 1,3-diketone and aromatic aldehydes under solvent-free conditions. The present methodology is cost-effective in addition to other advantages like high yields of products in shorter reaction time and simple workup procedure without the use of any injurious solvents.     

One-pot synthesis of various xanthene derivatives using ionic liquid 1, 3-disulfonic acid imidazolium hydrogen sulfate as an efficient and reusable catalyst under solvent-free conditions

In this study, 1,3-disulfonic acid imidazolium hydrogen sulfate （DSIMHS） is used as an efficient and reusable ionic liquid for the green, mild, and efficient synthesis of xanthenes under solvent-free conditions. Simple and easy work-up, low cost, green process, short reaction times and excellent yields of the products are the advantages of this procedure. Further, the catalyst can be recycled and reused at least for four times without a noticeably decrease in its catalytic activity.     

Synthesis of N-substituted-2-aminobenzothiazoles using nano copper oxide as a recyclable catalyst under ligand-free conditions in reusable PEG-400 medium

A simple and practical method for the synthesis of N-substituted-2-aminobenzothiazoles via a crosscoupling reaction of 2-iodo anilines with isothiocyanates is envisaged using nano copper oxide as a recyclable catalyst and Cs2CO3as a base in PEG-400,as a bio-degradable,reusable,inexpensive and nontoxic reaction medium,under ligand-free conditions.The present tandem process underlines environmental acceptability to access a wide range of N-substituted-2-aminobenzothiazoles in good to excellent yields.