制备参数对高比表面积介孔催化剂La-Co-Zr-O结构与性能的影响

采用双表面活性剂模板(十六烷基三甲基溴化铵和聚乙二醇辛基苯基醚的混合物)分解法制备了不同原子比(n_La+n_Co)/(n_La+n_Co+n_Zr)和不同温度焙烧的系列介孔混合氧化物催化剂La-Co-Zr-O。运用XRD、N₂吸附/脱附、XPS和H₂-TPR等技术对催化剂进行了表征，并以CO和C₃H₈氧化为模型反应，考察了组分配比和焙烧温度等参数对催化剂催化性能的影响。比表面积和孔径测试结果表明，样品具有很高的比表面积(108～266 m²·g^-1)和分布集中的孔径(3.4～3.9 nm)，Zr含量较高的样品比表面积较大。XRD结果表明，样品中的活性组分钴物种主要以Co₃O₄形式存在；XPS和H₂-TPR结果表明，样品中可还原的晶格氧的数量、活动度以及表面钴原子浓度均与催化剂对CO和C₃H₈的氧化性能密切相关。原子比为0.5的样品中，较多的晶格氧易于在相对低温下还原；而原子比为0.7的样品表面钴原子浓度较高，这使得两样品均表现出较高的催化活性。经650 ℃焙烧的样品仍保持较高的比表面积(108 m²·g^-1)和分布集中的介孔孔径(最可几孔径约3.8 nm)，且催化活性下降幅度也很小，表明该系列介孔催化剂具有优良的抗烧结能力和介孔热稳定性。     

Redox and spectroscopic orbitals in Ru(II) and Os(II) phenolate complexes

A detailed spectroscopic and electrochemical study of a series of novel phenolate bound complexes, of general formulas [M(L-L)(2)(box)](PF(6)), where M is Os and Ru, L-L is 2,2-bipyridine or 2,2-biquinoline, and box is 2-(2-hydroxyphenyl)benzoxazole, is presented. The objectives of this study were to probe the origin of the LUMOs and HOMOs in these complexes, to elucidate the impact of metal and counter ligand on the electronic properties of the complex, and to identify the extent of orbital mixing in comparison with considerably more frequently studied quinoid complexes. [M(L-L)(2)(box)](PF(6)) complexes exhibit a rich electronic spectroscopy extending into the near infrared region and good photostability, making them potentially useful as solar sensitizers. Electrochemistry and spectroscopy indicate that the first oxidation is metal based and is associated with the M(II)/(III) redox states. A second oxidative wave, which is irreversible at slow scan rates, is associated with the phenolate ligand. The stabilities of the oxidized complexes are assessed using dynamic electrochemistry and discussed from the perspective of metal and counter ligand (LL) identity and follow the order of increasing stability [Ru(biq)(2)(box)](+) < [Ru(bpy)(2)(box)](+) < [Os(bpy)(2)(box)](+). Electronic and resonance Raman spectroscopy indicate that the lowest energy optical transition for the ruthenium complexes is a phenolate (pi) to L-L (pi) interligand charge-transfer transition (ILCT) suggesting the HOMO is phenolate based whereas electrochemical data suggest that the HOMO is metal based. This unusual lack of correlation between redox and spectroscopically assigned orbitals is discussed in terms of metal-ligand orbital mixing which appears to be most significant in the biquinoline based complex.     

掺铜KNSBN光折变晶体的光致吸收特性

掺铜KNSBN(钾钠铌酸锶钡)光折变晶体具有光致吸收(LIA)特性.实验表明,泵浦光的光强越强,波长越短,LIA系数就越大,探测光为e偏振态时的LIA系数是o光时的1.2倍.这种现象将被用来提高光场的空间或时间均匀性.     

PEG化氘代单磷酸三苯甲基自由基的高效合成及性能研究

电子顺磁共振（EPR）波谱联用外源性自旋探针技术是测量体内外pH的有效手段.有研究表明，单磷酸取代三苯甲基（p₁TAM）自由基是目前用于检测pH的最理想的EPR探针.然而，这类探针的合成产率低、易受蛋白影响，极大限制了其生物应用.针对上述问题，本文提出了高效合成p₁TAM自由基的方法，使其总产率从文献报道的1.6%提高到了25%；同时采用PEG修饰的方法避免了白蛋白（BSA）对其产生的干扰.进一步氘代实验结果证实：非氘代PEG化（p₁TAM-H）衍生物（POP）虽与氘代PEG化（p₁TAM-D）衍生物（dPOP）具有相似的pH敏感性（其pKa分别为6.80和6.79），但POP的EPR谱图较为复杂，而dPOP无论在低pH还是在高pH条件下均具有简单的EPR双峰信号；而且，dPOP具有比POP和p₁TAM-H更好的检测灵敏性；此外，dPOP还具有较好的生物稳定性和氧气敏感性.因此，dPOP能够用来同时检测pH和氧气，有望在生物医学方面得到更好的应用.     

THF-FER沸石的系列研究IV.固体酸性及C5烯烃骨架异构化催化性能

在四氢呋喃(THF)-Na2O-SiO2-Al2O3-H2O体系中水热合成的THF-FER沸石，经酸交换／焙烧或焙烧／酸交换处理可制得H-FER-1和H-FER-2两种H型沸石．红外光谱及NH3-TPD等实验结果表明，两者的强酸位主要是对烯烃骨架异构化反应有贡献的Bronsted酸位．1073K／10h的高温水蒸汽处理会导致沸石骨架脱铝，但并未产生过多的末端硅羟基．两者比较，H-FER-1沸石的结构缺陷较少，Bronsted酸位较多，骨架更完美．由THF-FER沸石制备的H-FER催化剂，对C5正构烯烃骨架异构化反应显示了优良的催化活性、选择性及稳定性．