碳载铂电极对乙二醇氧化的电催化性能研究

运用电化学循环伏安，阶跃电位，以及Ｘ－光衍射和扫描电镜等方法，研究了玻碳表面高分散铂电催化剂在不同条件下的结构与性能，结果指出，玻碳表面沉积的高分散铂黑经高温处理后具有一定的择优取向，晶粒尺寸变大，具有更好的稳定性和对乙二醇的电催化活性。     

用布基球固氮

据日本Kyoto大学的SakaeUemura小组报道,以不含金属的布基球为基础的体系,能够将氮分子转化为氨。在现有的生物的、工业的以及过去已报道过的均相合成体系中,固氮过程均依赖于金属的氧化还原性质。而Uemura的体系却是两端各有一个γ-环糊精分子的C60。在1atm氮的气氛下,于60℃,用这种复合物在水中的悬浊液和100当量的亚硫酸钠处理1h后,氨的产率可达33%。该反应对于温度、中性的pH、和反应物的组合要求极为严格。该小组认为光照对于实现电子从富电子的C60-环糊精向N2的转移应当有帮助。因为实验表明,在无光照时,反应不会发生。而用高压汞…     

A Novel Amperometric Nitric Oxide Sensor Based on Polythionine / Nation Modified Glassy Carbon Electrode

A novel amperometric sensor for the determination of nitric oxide was developed by coating polythionine / nafion on a glassy carbon electrode. This sensor exhibited a great enhancement to the oxidation of nitric oxide. The oxidation peak currents were linear to the concentration of nitric oxide over the wide range from 3.6×10-7 to 6.8×10-5 mol.L-1, and the detection limit was 7.2×10-8 mol.L-1. Experimental results showed that this nitric oxide sensor possessed excellent selectivity and longer stability. NO releasing from rat kidney was monitored by this sensor.     

Ce-Pt-Pd/不锈钢丝网催化剂的制备与催化性能

采用阳极氧化技术在不锈钢丝网上自生长了一层结构致密的阳极氧化膜,并以此为载体,制备出一种高活性、高稳定性的负载型Ce-Pt-Pd催化剂.考察了该系列催化剂对甲苯、丙酮和乙酸乙酯的氧化活性,并用扫描电镜、X射线光电子能谱和程序升温氧化技术对催化剂进行了表征.结果表明,不锈钢丝网载体表面自生长的氧化物膜十分有利于活性组分的负载,制得的催化剂具有较高的催化燃烧有机化合物的活性和稳定性.     

Synthesis of a New Type of Amphilic and Water—soluble Tertiary Phosphine Ligands Substituted by an Ethoxylated Phosphonic Acid Chain and Their Palladium Complexes

The highly water-soluble phosphine ligands Na2O3PCH2CH2NH(CH2CH2O)nCH2CH2N-(CH2PPh)22(n=1,2,3) were prepared by a new and simple route under mild conditions in good yield; the palladium (Ⅱ） complexes of the ligands 3a-c with 2:1 or 4:1 -PPh2 to Pd^2 molar ratio were also prepared and characterized.     

Determination of the Potential Barrier at the Metal／Oxide Interface in a Specular Spin Valve Structure with Nano—oxide Layers Using Electron Holography

The local potential distribution in a specular spin valve structure with nano-oxide layers has been mapped by using off-axis electron holography in a field emission gun transmission electron microscope.A potential jump of 3-4 V across the metal/oxide interface was detected for the first time.The presence of the potential barrier confirms the formation of the metal/insulator/metal structure,which contributes to the increasing mean free path of spin-polarized elecrons via the specular reflection of spin-polarized electrons at the metal/oxide interface.It leads to nearly double enhancement of the magnetoresistance ratio from 8% to 15%.     

甲烷在金属氧化物上催化脱氢的从头计算

用Ｇ９４的从头计算方法对甲烷在金属氧化镁及氧化锂表面上不同氧物种Ｏ＾－，Ｏ＾２－２，Ｏ＾－２，Ｏ＾２－催化脱氢进行了理论研究，确定了过渡态的几何构型，集居分布和反应活化能。结果表明，氧物种的催化脱氢的活性顺序为Ｏ＾２－２≈Ｏ＾－〉Ｏ＾－２〉Ｏ＾２－。其中Ｏ＾－２物种由于对甲烷具有较低的氧化能力而可能是ＯＣＭ活性和高Ｃ２选择性的氧物种。