The hydroxyl species and acid sites on diatomite surface: a combined IR and Raman study

Diffuse reflectance infrared Fourier transform spectroscopy (DRIFT), Raman spectroscopy of adsorbed Pyridine molecules (Py-Raman) and in situ Py-IR have been used to investigate the hydroxyl species and acid sites on diatomite surfaces. The Lewis (L) and BrØnsted (B) acid sites, and various hydroxyl species, including isolated hydroxyl groups, H-bonded hydroxyl groups and physically adsorbed water, are identified. The L acid sites in diatomite samples are resulted from the clay impurities, and the B acid sites are resulted from some moderate strength H-bonded hydroxyl groups. At room temperature, both of the isolated and H-bonded silanols associate with the physically adsorbed water by hydrogen bond. After calcination treatment, physically adsorbed water will be desorbed from the silanols, and the silanols will condense with the increase of temperature. Generally, the H-bonded silanols condense more easily than the isolated ones. The properties of surface hydroxyl species of diatomaceous silica are more similar to precipitated silica rather than fumed silica

The Synthesis of cis-3-Hexen-1-ol

己二烯酸经酯化后再在 Zn O/Cd O存在下催化氢化合成顺 -3 -己烯 -1 -醇。在 1 50℃ ,1 .2 1× 1 0 7Pa氢压下获得了 50 .6%的收率。cis 3 Hexen 1 ol was prepared by selective hydrogenation of hexadienic ether, which was obtained through esterification of hexadienic acid and anhydrous alcohol, at 150℃ under hydrogen pressure about 1.21×10 5Pa in the presence of CdO/ZnO as a catalyst with the yield about 50.6%. The result of experiment shows the new method is a feasible route for synthesizing cis 3 hexen 1 ol

甲酸甲酯氢解制甲醇铜基催化剂上吸附物种的现场红外光谱表征

应用原位红外光谱的方法，在反应现场条件下，研究了促进型甲酸甲酯（ＭＦ）氢解制甲醇铜铬催化剂上的化学吸附物种．结果表明，在ＭＦ氢解反应条件下，工作态催化剂上主要的化学吸附物种和反应中间物种是ＣＨ３Ｏ－ＣＨＯ…Ｈ－Ｏ（ａ）（１７５１，２７３０，１４５５ｃｍ－１）、ＣＨ３Ｏ－ＣＨＯ…Ｃｕ＋（ａ）（１６５４，２７３０，１４５５ｃｍ－１）、ＣＨ３Ｏ－ＣＨＯ…Ｃｒ３＋（ａ）（１５５２，２７３０，１４４５ｃｍ－１）和ＯＣＨ３（３０１２，２９４６，１４５５ｃｍ－１）．结合对该催化剂活性位本质的探讨，推断了甲酸甲酯氢解制甲醇的主要反应途径

改进型铜基甲醇合成催化剂XC209的热稳定性

在 Cu- Zn- Al三组份的 C2 0 7型联醇催化剂中 ,添加 2种适量的过渡金属氧化物研制的XC2 0 9型联醇催化剂 ,经 4 50℃热处理 5h后 ,CO转化率比 C2 0 7型提高 8.6个百分点 .XRD和FTIR表征显示 ,工作态的改进型催化剂表面 Cu+ 活性浓度比 C2 0 7型高 ,热处理后能维持工作表面具有较大的 Cu+ /Cu°比 ,金属间相互作用加强了 ,这与改进型催化剂具有较高的热稳定性密切相关

FTIR-ATR Spectrometry of BSA Adsorption on Hydroxyapatite

采用傅里叶变换红外衰减全反射(FTIR-ATR)光谱法对牛血清白蛋白(BSA)在羟磷灰石(HA)[Ca_(10)(OH)_2(PO_4)_6]表面不同时间的相互吸附作用进行了表征。在BSA溶液作用下,羟磷灰石表面的Ca~(2+)、PO_4~(3-)和OH~-离子初始的溶解和再沉淀使得BSA与HA相互作用层层叠加,在HA表面形成从表层到次表层分子都包含有吸附的BSA的覆盖层,从而加深两者之间的相互作用。经红外差谱法处理过的相关ATR数据表明,BSA与HA之间的相互作用是快速的,并随时间变化进一步加强;来自HA上PO_4~(3-)的P=O基团对蛋白质肽键的酰胺Ⅱ带(-CNH)、多肽链的甲基(-CH_3)和亚甲基(-CH_2)上氢的吸附作用要比P-O快速而且强烈。Ca~(2+)在该吸附过程中起了极其重要的作用,其快速与蛋白质肽键的羰基氧发生作用,并诱导该蛋白质二级结构由β-折叠向α-螺旋和β-转角构象转变;伴随着这一构象变化,蛋白质多肽链上大多数肽键的-C=O和H-N-活性基团从链间氢键交联中释放出来,带动众多的氢分别参与同HA表面的Ca~(2+)、PO_4~(3-)和OH~-离子的相互吸附作用,并牢牢地结合于HA表面;这对硬组织的再生起着重要作用,促进了HA的生物矿化过程。The microcosmic process of bovine serum albumin(BSA) adsorbing onto hydroxyapatite(HA) for different time intervals was investigated by Fourier transform infrared attenuated total internal reflectance(FTIRATR) spectrometry.The initial dissolution and re-precipitation of PO_4~(3-),Ca~(2+),and OH~- ions from the HA coating led to the occurrence of the coating including adsorbed BSA on the HA from surface-to subsurface-molecular layers and to in-depth interaction between BSA and HA.The subtraction results gained in the adsorption regions of HA and BSA reveal that the binding of P=O,from the phosphate(PO_4~(3-)),to the hydrogen of amide Ⅱ,methyl and methene of the BSA appears to be considerably more rapid and stronger than that of the P—O group.In addition,it is very likely that Ca~(2+) plays an important role in the interaction of BSA with HA.It appears that the binding of Ca~(2+) to the carbonyl-oxygen of the peptide bond in BSA caused a significant,molecular,conformational rearrangement of polypeptide backbones from β-pleated sheet to helical circles of α-helix and β-turn.This change appears to have been followed by much hydrogen of polypeptides being driven to bind PO_4~(3-) and OH~-effectively and much-C=O and H-N- groups of the peptide bond being freed from inter-chain hydrogenbonding to act on Ca~(2+) and combine strongly with the HA surface.This might reasonably be expected to promote hard tissue regeneration.BSA seems to be activated by the inductive effect of Ca~(2+) via the molecular rearrangement of polypeptide backbones from pleated sheet to helical circles and in turn reacts strongly on the HA,resulting in profound effects on the course of biomineralization.国家自然科学基金(51571169)资助项目~

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

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

长链DNA在金基底上的固定化和电化学标记

本文提出在金基底上用阳离子聚电解质———聚二烯丙基二甲基胺氯化物 (poly(dial lyldimethylammoniumchloride) ,PDDA)自组装膜固定长链DNA的方法 ,用DiffuseReflectanceIn frared ,XPS和STM技术进行表征 ,并对DNA杂交进行电化学标

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