Relationship between surface microstructure and properties of supported catalyst Rh/Ys

The inner structure of Rh/Ys,a novel high efficiency supported catalyst,and the spreading of Rh on the Ys surface were analyzed through electron transmission microscopy and scanning tunnel microscopy.The relationship between the distribution of Rh over the support and the preparation temperature of th catalyst was determined.The formation of Rh-C bond was confirmed by XPS and far-IR spectra.The loss of Rh from the surface of the support and the catalytic activity under different preparation conditions have been compared.The internal factors for the high activity and high stability of the novel Rh/Ys catalyst have been discussed.     

POLYKETONE FROM CO AND STYRENE: A USEFUL COPOLYMER CATALYZED BY A HIGHLY ACTIVE AND STABLE PALLADIUM CATALYST WITH 5-NITRO-1,10-PHENANTHROLINE LIGAND

A novel coordinated complex [(5-nitrophen)Pd(CF3CO2)2] (5-nitrophen = 5-nitro-l,10-phenanthroline) was first synthesized. By using XPS, IR, and 1H-NMR, its coordination unit was studied in comparison with those of complexes [(N- N)Pd(CH3CO2)2] and [(N - N)Pd(CF3CO2)2]. The H2,9 proton signals of 1H-NMR spectra of the complexes are excellent probes to monitor the evolution of the environment of the palladium atom. The state of anionic coordination was confirmed by the presence of IR absorption peaks of COO in complexes ([(N N)Pd(CH3CO2)2] and [(NN)Pd(CF3CO2)2]). Bonding energies of N1s and Pd3d5 obtained from XPS data testified to the strength of the N-Pd coordinating bond. The conclusion can be drawn by analyzing these data from IR, XPS and 1H-NMR that it is the unsymmetrical substitution of the 1,10-phenanthroline (phen) that makes the [(5-nitrophen)Pd(CF3CO2)2] more active.Experimental results showed that [(5-nitrophen)Pd(CF3CO2)2] exhibits much higher activity than [(bipy)Pd(CF3CO2)2] (1, l‘-bipyridine = bipy) and [(phen)Pd(CF3CO2)2] under the same conditions.     

Kinetic studies on vapor phase carbonylation of methanol to acetic acid over Rh/Ys catalyst

A novel catalyst Rh/Ys for the carbonylation of methanol to acetic acid with CH3I as the promoter shows excellent activity and selectivity.The reaction is kinetically controlled.The reaction rate is in proportion to the concentration of Rh and CH3I but has nothing to do with those of CH3OHH and CO.The surface active energy is Ea ~51.02 kJ/mol.A mechanism is also proposed.     

介孔ZnO/SiO2复合材料的合成与性能表征

通过原位合成的方法,以[Zn(OH)x]-(x-2)(x＞2)为锌源、正硅酸乙酯(TEOS)为硅源,合成了孔壁为ZnO/SiO2复合结构的MCM-48型有序介孔分子筛,并通过XRD、XPS、N2吸附-脱附等温线等手段对样品进行了表征,结果表明,锌以正二价离子的形式均匀的分布在MCM-48分子筛的孔壁结构中.另外,适量掺锌所合成的Zn-MCM-48介孔材料仍然保持立方介孔的有序结构,具有较高的比表面积、较高的孔容和较宽的孔径分布.     

Improvement on stability of square planar rhodium (Ⅰ) complexes for carbonylation of methanol to acetic acid

A series of square planar cis-dicarbonyl polymer coordinated rhodium complexes with uncoordinated donors near the central rhodium atoms for carbonylation of methanol to acetic acid are reported. Data of IR, XPS and thermal analysis show that these complexes are very stable. The intramolecular substitution reaction is proposed for their high stability. These complexes show excellent catalytic activity, selectivity and less erosion to the equipment for the methanol carbonylation to acetic acid. The distillation process may be used instead of flash vaporization in the manufacture of acetic acid, which reduces the investment on the equipment.     

气相色谱的定量分析方法Ⅰ.以空气作标准的热导池气相色谱定量方法的研究

本文在相对灵敏度理论基础上,提出以空气作相对标准的气相色谱定量方法,并引进空气标定因子作为应用这一方法的定量参数.有关气体在热导池检测器中的空气标定因子,根据Novák提出的相对克分子响应关系式^[1]计算得到的结果,其准确度可以满足一般情况下热导池气相色谱定量分析的精度要求.     

异戊二烯-甲基丙烯酸甲酯共聚物微结构和竞聚率的250兆氢-1核磁共振研究

本文由异成二烯-甲基丙烯酸甲酯共聚物的250兆赫氢-1核磁共振谱,定量地研究了共聚物中微结构单元及其组成。应用镨、铕两种位移试剂,通过观察1,4-异戊二烯双键质子峰的分离,测定了以1,4-戊戊二烯为中心的三元组分布,甚至五元组分布。确定了该体系的自由基共聚存在末前位效应,二级马尔克夫链模型的相应的竞聚率常数分别为:r_II=0.48,r_MI=0.86,r_MM=0.15,r_IM=0.43。以1,4-异戊二烯为中心的五元组分布和以甲基丙烯酸甲酯为中心的三元组分布的实验测定值与上述结果是一致的。     

正方平面顺二羰基(二齿N-配体)铑(Ⅰ)阳离子配合物的XPS研究

用XPS研究了十五个[Rh(CO)_2(che1l]BPh_4系列配合物的结构、配位形式及电荷分布、结果表明,配位时电荷转移的行径为:(1)Rh←CO;(2)Rh←N;(3)[Rh(CO)_2(chel)~+→B.同时,每一配合物铑原子的价电子密度与配体有关。     

碳氮复合材料负载镍甲醇羰基化催化剂的研究

通过碳化由偏氯乙烯和丙烯腈悬浮共聚得到的前体,制得碳氮复合材料,将其负载金属镍后即得气相甲醇羰基化反应的催化剂。分别采用扫描电镜(SEM)、氮气吸附、XPS、电子探针(EPMA)等方法对该材料及由其制得的催化剂进行表征,证明该催化剂中的镍呈高度分散的纳米粒子状态。采用固定床反应器对该催化剂进行催化性能测试,结果表明该催化剂在较低金属镍负载量及较温和的条件下即可具有较好的催化性能。该催化剂的最佳镍负载量为1.5%左右。