合成乙酸乙酯的方法及其催化剂

从合成原料出发,综述了制备乙酸乙酯的方法及其催化剂的研究进展,着重介绍了以乙酸和乙醇为原料的固体酸催化剂及其液固相和气固相反应,以乙醇为原料的一步法合成的混合氧化物催化剂及其气固相反应

微生物吸附贵金属的研究与应用

概述了微生物吸附回收金、银、铂、钯等贵金属的研究进展 ,微生物吸附贵金属的机理 ,生物吸附技术在贵金属回收等方面的应用及前景。国家自然科学基金资助项目 (No 2 974 30 0 1 ,2 9876 0 2 6 )~

聚酰胺硅胶吸附茶多酚的红外光谱研究

IR谱表明:聚酰胺硅胶吸附剂中,聚酰胺的N—H和硅胶表面OH以氢键结合,υC=O无位移;室温下该吸附剂中C=O和茶多酚中O—H作用后,υC=O和υO—H分别红移了11cm-1和18cm-1;而与咖啡因及氨基酸作用后υC=O无位移

微生物还原制备高分散度负载型钯催化剂

用地衣形芽孢杆菌 ( Bacillus licheniformis) R0 8菌体还原、制备高分散度负载型钯催化剂。透射电镜观察表明 ,R0 8菌体能够吸附还原 Pd2 +成 Pd0 颗粒。IR谱分析发现 ,细胞壁上的 - COO- 和 - HPO42 - 基团可能与菌体吸附 Pd2 +的过程有关。XPS测定结果表明 ,在载体 γ- Al2 O3上的 Pd2 +离子被 R0 8菌体还原成 Pd0。所形成的 Pd0 γ- Al2 O3催化剂经加热处理后 ,载体 γ- Al2 O3上的 Pd0 颗粒高度分散 ,其平均粒径为 5nm。该催化剂能够高效地催化一氧化碳的氧化反应

细菌还原Au--(3+)制备金催化剂的研究

从不同来源的细菌菌株筛选获得一株吸附还原Au3＋较强的菌株d01，经鉴定为巨大芽孢杆菌（bACIluSMEgATHErIuM）d01。菌株d01在Au3＋浓度600Mg/l下仍能较好生长。从电化学反应表明，该菌具有较强的还原力，它能将金催化剂的前驱体Au3＋/αfE2O3还原成具有催化CO＋O2→CO2的高分散度的Au0/αfE2O3催化剂国家自然科学基金;固体表面物理化学国家重点实验室资

用辛烷基硫醇单层保护Au纳米粒子制备CO氧化催化剂Au/γ-Al_2O_3

采用两相法合成出含活性组分Au的辛烷基硫醇单层保护Au纳米粒子(C8AuNPs)的正己烷溶胶,用"逐次浸润"法将C8AuNPs负载在γ-Al2O3上,经真空干燥及活化处理制得Au/γ-Al2O3催化剂.所制得的Au催化剂前体C8AuNPs/γ-Al2O3表面Au粒子平均粒径可控制在2-3nm范围内,且分布比较单一;催化剂活性评价600h后,其表面Au的粒径仍主要分布在2-4nm范围内;真空干燥温度影响Au催化剂的粒子尺寸和催化活性,随着真空干燥温度的提高,Au纳米粒子的粒径增大.将所制备的催化剂用于低温CO氧化反应,催化活性评价结果表明,经25℃真空干燥制得的2.5%(质量分数,w)Au/γ-Al2O3具有较高的活性和长期稳定性,其催化CO完全转化的最低温度为-19℃,在15℃下CO完全转化时Au/γ-Al2O3的单程寿命至少900h;4.0%(w)Au/γ-Al2O3在15℃和进料中含水条件下对CO完全氧化的单程寿命不低于2000h,可见催化剂具有强的抗潮湿中毒特性.综合上述实验结果,讨论了影响Au/γ-Al2O3催化剂活性的可能因素

Spectroscopic Characterization on Interaction of Gold (Au ~(3+)) Biosorption by Bacillus megaterium D01

对休眠的巨大芽孢杆菌 (Bacillusmegatherium)D0 1菌体吸附Au3 + 的作用过程进行了谱学表征 .运用AAS考察了pH、时间和温度对D0 1菌体吸附Au3 + 过程的化学动力学和热力学相关参数的影响 .D0 1菌粉中硫元素含量的EDX分析说明该菌体中对Au3 + 具有还原作用的L 半胱氨酸和蛋氨酸的含量极少 ;D0 1菌体水解后葡萄糖含量的UV vis测定说明该菌体水解产物中含有一定量的还原糖 .空白的和吸附Au3 + 的D0 1菌体的FTIR检测表明该菌体细胞壁肽聚糖层糖类化合物的羟基和肽链侧链氨基酸残基离子化羧基为吸附Au3 + 的活性基团 ;肽聚糖层部分多糖的水解产物低聚糖、二糖及单糖等还原糖的半缩醛羟基游离态醛基为电子供体 ,将Au3 + 原位还原成Au0 .葡萄糖和Au3 + 相互作用的XRD和FTIR表征证明Au3 + 是在还原糖的醛基上直接被还原成Au0Biosorptive interaction of gold with resting cell of Bacillus megatherium D01 biomass has been characterized by spectroscopic techniques. The effects of pH, time and temperature on the correlation parameters of chemical kinetics and thermodynamics of the binding reaction has been investigated through the determination of the gold ion binding to the biomass using atomic absorption spectrophotometry (AAS). The analysis for sulfur content in dry powder of the D01 biomass by energy dispersive X-ray (EDX) shows that cysteine and methionine being capable of reducing Au 3+ to Au0 is very small, whereas the glucose content in hydrolysates of the biomass analyzed by ultraviolet-visible spectrophotometry (UV-vis) indicates that the amount of the reducing sugars in the biomass is much larger than 3.33%. The Fourier transform infrared (FTIR) spectroscopy on blank and gold-loaded biomass demonstrates that the active groups such as the hydroxyl group of saccharides and the ionized carboxyl group of amino acid residues on the cell wall seem to be the sites for Au 3+ binding, and the free aldehyde group of the hemiacetalic hydroxyl group from reducing sugars, i.e. the hydrolysates of the polysaccharides, serving as the electron donor, in situ reduces the Au 3+ to Au0. X-ray powder diffractometry (XRD) and FTIR spectroscopic characterizations of the interaction of Au 3+ with glucose confirm that the reduction of Au 3+ to Au0 can directly occur in the aldehyde group of the reducing sugars

茶叶中茶多酚的吸附分离提取

研制了聚酰胺/硅胶负载型吸附剂并用于提取茶叶中的茶多酚。该吸附剂对茶多酚的吸附能力与硅胶的平均孔径和聚酰胺的负载量有关，硅胶平均孔径以12-13nM为宜；聚酰胺的担载量以10~20WT%效果最佳。该吸附剂对茶多酚的提取率约12%；制品纯度为85%─90%可直接用于食品加工工业

Preparation of Supported Palladium Catalyst by Bioreduction

［中文文摘］将微生物可在常温下还原贵金属离子的特性引入催化剂的制备过程中,利用对Pd2+具有较强还原能力的地衣芽孢杆菌(简称R08)制得负载型Pd催化剂(简称催化剂)。采用X射线光电子能谱(XPS)和透射电镜(TEM)对催化剂进行表征。XPS测定结果表明,室温下R08菌体可将γ-A l2O3载体表面上的Pd2+基本还原为Pd0;生物还原法制得的催化剂的Pd微粒的平均粒径约为5nm。将该催化剂用于2%CO-98%空气(体积分数)混合气的催化氧化反应,CO完全氧化的最低反应温度为60℃,在此温度下催化剂的活性可恒定150h,结果优于相同条件下化学浸渍法制得的催化剂。XPS表征和催化活性评价结果说明,用于CO催化氧化反应的催化剂中单原子Pd活性中心的价态为0~+2。［英文文摘］Pd catalyst supported on γ2a lumina ( nanoparticles) with high dispersion was prepared by bioreduction with Bacillus lichenifoum is ( strain R08) , which was strong in reducing ab ility of Pd2 + . Catalysts prepared by bioreduction and impregnation were cha racte rized by m eans of XPS and TEM.XPS spectra indicated tha t s train R08 could almost completely reduce Pd2 + to Pd0. TEM images showed that average sizes of Pd particles on catalysts prepared by bioreduction and by impregnation were 5 nm and 18 nm, respectively. When catalyst p rep ared by bioreduc tion w as used in ox idization of carbon m onoxide to carbon dioxide, the carbon monoxide could be comp letely oxidized at the lowest temperature of 60 ℃and activity of catalyst could be main tained a t this tempe rature fo r 150 h. The result was better than catalyst prepared by imp regnation. Pd ( Ph2 PCH2 PPh2 ) 2 suppo rted on γ2alum ina was synthesized as catalyst for the oxidation. Results of XPS spectra and activity eva luation indicated that chemical valence state of Pd on active center of catalyst was between 0 and + 2.国家自然科学基金项目(20376067

Study on the Reduction of Supported Noble Metal Ions Using Bacteria

负载型贵金属离子细菌还原的探索研究傅锦坤于新生林种玉胡荣宗（固体表面物理化学国家重点实验室厦门大学化学系厦门361005）刘月英姚炳新翁绳周（厦门大学生物学系厦门361005）生物化学法制备高分散度贵金属（rH、PT、Pd、Ag、Au）催化剂的研究中...The Gram positive bacteria strain D01 selected From various samples, are possessed of the stronger reducing ability. Its culture was easy. Supported Rh 3+ , Pt 4+ , Pd 2+ , A + g, Au 3+ could be adsorbed and reduced by this bacteria.The results obtained by IR techniques shown that there was the biochemistry action between the bacteria and the noble metal ions. Using the cyclic voltammograph method indicated that the reducing ability of the bacteria were stronger. XPS experiments Further indicated above noble ions could be reduced by this bacteria with diFFerent degree, the reduction did not be inFluenced by the kinds of noble metal ions and supports. The results shown that the properties of redox of above noble metal ions For electron transFer were the same. The preparation of Au catalyst with high dispersion ( Au 0 For nanometer particles ) on (Fe 2O 3)was also studied.国家自然科学基金（风险基金）;固体表面物理化学国家重点实验室基