Pt／YSZ固体电解质界面氧的电荷传递过程研究

用极化法研究了不同温度和氧分压下Ｐｔ／ＹＳＺ界面氧的电荷传递过程．研究发现氧电荷传递过程的阴、阳极电荷传递系数为１，不随温度和氧分压而变．从实验和反应机理推导得到，Ｐｔ／ＹＳＺ界面的交换电流密度和氧分压之间存在，ｉ０＝２ＦＫｒ（ＫＯ２ＰＯ２）１／４（１＋ＫＯ２ＰＯ２）１／２的关系．通过数学分析还获电化学反应速度常数，氧在Ｐｔ表面上吸附平衡常数等重要参数     

β-二酮钛配合物/甲基铝氧烷催化体系用于苯乙烯的间规聚合

β 二酮钛配合物／甲基铝氧烷催化体系用于苯乙烯的间规聚合许学翔谢光华（中国科学院化学研究所北京１０００８０）关键词β 二酮钛配合物，苯乙烯，甲基铝氧烷，间规聚合苯乙烯聚合物可分为无规聚苯乙烯（ａ ＰＳ），等规聚苯乙烯（ｉ ＰＳ），间规聚苯乙烯（ｓ?..     

碱性燃料电池氧电极的研究：助催化剂的添加对Ag／C催化剂活性的影响

本文报道了一种新的用于碱性燃料电池氧电极的非贵金属催化剂．此种以化学还原法制备的Ａｇ－Ｎｉ－Ｂｉ－Ｈｇ－／Ｃ催化剂对氧电极的阴极还原具有较高的活性，当催化剂的组成为Ａｇ５０％－Ｎｉ２％－Ｂｉ３％－Ｈｇ３％－Ｃ４２％（ｗｔ％）时，催化剂的活性最佳．ＸＲＤ和ＳＥＭ证实，助催化剂的加入使银的结晶趋于无定型化，减小了银结晶的尺寸．经过５２００ｈ的寿命考察，催化剂活性没有明显的改变．     

脉冲反应技术研究气相氧和晶格氧对甲烷氧化偶联的作用

ＣａＯ的晶格氧对甲烷能发生非选择性氧化反应，经反应消耗的晶格氧可以由气相氧中补充，也可以通过体相晶格氧向表面的迁移来补充。Ｎａ￣＋添加剂能抑制ＣａＯ晶格氧的反应活性，当Ｎａ￣＋含量达到５％时，ＣａＯ晶格氧对甲烷的完全氧化活性被完全抑制。Ｃａ＿ｘＳｒ＿（１－ｘ）ＴｉＯ＿３复合氧化物催化剂的晶格氧对甲烷没有活性。只有当气相氧存在时，在５％Ｎａ￣＋／ＣａＯ和Ｃａ＿ｘＳｒ＿（１－ｘ）ＴｉＯ＿３复合氧化物上才能通过气相氧向表面氧物种的转化而引发甲烷氧化偶联反应。     

La0.8Sr0.2MnO3/YSZ电极氧电化学还原反应动力学

用线性极化、循环伏安、电位阶跃等方法详细研究了Ｌａ０．８Ｓｒ０．２ＭｎＯ３／ＹＳＺ高温电极上进行的氧化学还原反应。实验结果表明，该反应存在两条路径：低温下氧还原反应主要发生在气相－ＬＳＭ电极－ＹＳＺ电解质接触的三相界面（ＴＰＢ），速度控制步骤为氧原子在ＬＳＭ表面的浓差扩散，高温下由于氧空位在ＬＳＭ表面的形成，氧还原反应区扩展至ＬＳＭ电极表面，速度控制步骤为氧的电荷转移反应，实验同时发现：氧空位的形     

多晶铑表面上碳氧共存体系的研究

用紫外光电子能谱（ＵＰＳ）和俄歇电子能谱（ＡＥＳ）对碳氧共存的多晶铑表面及ＣＯ、Ｏ_２、Ｃ_２Ｈ_４在该表面上的吸附进行了研究，发现铑表面上共存的表面碳和表面氧存在相互作用，由于表面氧的存在，外来吸附物如ＣＯ、Ｏ_２、Ｃ_２Ｈ_４等可以覆盖在表面碳上面，使表面碳占据表面位抑制其它物种吸附的屏蔽效应消失。该表面具有氧化性，可以把吸附的乙烯氧化。     

氧泵型催化膜反应器中甲烷氧化偶联反应—SEM和XPS研究

氧泵型催化膜反应器中甲烷氧化偶联反应—ＳＥＭ和ＸＰＳ研究国秀梅，陈洪钫（天津大学化工系，天津３０００７２）关键词甲烷氧化偶联，氧泵型催化膜反应器，ＳＥＭ，ＸＰＳ由于氧泵型催化膜反应器具有可简化分离过程，改变催化剂性质，控制传递氧量，避免副反应发生等优...     

Bi－Mo－Nb复合氧化物催化作用机理的ESR和XPS研究

用ＥＳＲ对比研究了掺杂Ｎｂ对α－Ｂｉ２Ｍｏ３Ｏ（１２）催化剂丙烯还原和氧再氧化的影响，并用ＸＰＳ原位Ａｒ＋溅射研究了催化剂的还原与再氧化过程，观察了上述过程中催化剂内金属离子的价态变化和晶格氧的扩散现象。提出了Ｂｉ－Ｍｏ间通过晶格氧扩散所发生的氧化还原作用及模型，探讨了Ｎｂ（５＋）取代Ｍｏ（６＋）产生的氧空位对加速晶格氧扩散所起的作用。     

MoO3和α-Sb2O4相间氧溢流行为的研究

通过脉冲还原技术和量子化学ＤＶ－Ｘα方法研究了ＭｏＯ３和αＳｂ２Ｏ４相间氧溢流行为，揭示了有关氧溢流的动力，溢流氧的本质及可能在溢流途径的信息，结果表明，氧溢流是α－Ｓｂ２Ｏ４自发氧化ＭｏＯ３的结果，不依赖于气相氧的存在，溢流氧是亲核性的，但依赖于亲电性晶格氧的存在，溢流氧主要被ＭｏＯ３的（０１０）面所接收，对用ＤＶ－Ｘα法进行固体氧化物电子性质研究的可行性也进行了探讨。     

Na-W-Mn/SiO2催化剂活化甲烷的研究Ⅱ.活性氧物种

制备了不同Ｎａ、Ｗ、Ｍｎ组分的Ｎａ－Ｗ－Ｍｎ／ＳｉＯ２催化剂,并进行了Ｏ２程序升温脱附（Ｏ２－ＴＰＤ）和不同温度下Ｎａ－Ｗ－Ｍｎ／ＳｉＯ２催化剂的ＣＨ４脉冲反应（ＣＨ４－ＰＲ）。研究结果表明,Ｎａ－Ｗ－Ｍｎ／ＳｉＯ２催化剂活化甲烷的活笥氧物种是Ｗ和Ｍｎ提供的、高温下易于流动的表面晶格氧（Ｏ＾２－）。Ｎａ和Ｏ＾２－的活泼性具有重要的促进作用,它可以极化Ｗ、Ｍn的金属一氧键,促进Ｏ＾２－的流动性。Ｎａ     

掺杂ZrO＿2的Pt／Al＿2O＿3表面氧性质及一氧化碳氧化性能研究

用ＴＰＤ－ＭＳ、ＴＰＳＲ－ＭＳ及ＣＯ氧化活性测定等方法研究了Ｐｔ／Ａｌ２Ｏ３和掺杂超细ＺｒＯ２的样品的表面氧脱出－恢复性能、ＣＯ表面氧化性能及催化氧化性能．结果表明，在Ｐｔ／Ａｌ２Ｏ３中掺杂ＺｒＯ２后，样品表面上的氧物种脱出和氧化恢复性能明显提高，脱氧量也明显增大；并发现在ＣＯ－ＴＰＳＲ过程中程脱物ＣＯ２的脱附量大小及峰顶温度次序与对ＣＯ的催化氧化活性也有一致的关系     

静电纺丝法制备纳米氧化铟锡及其导电性能

采用静电纺丝-溶胶凝胶法,以SnCl2、InCl3、聚乙烯吡咯烷酮(PVP)等为原料,乙醇胺为水解控制剂,合成了超细氧化铟锡(ITO)纳米纤维及富氧缺陷的ITO纳米颗粒.采用透射电子显微镜(TEM)、选区电子衍射(SAED)、扫描电子显微镜(SEM)、热重分析(TGA)、X射线衍射(XRD)、X射线电子能谱(XPS)、...     

氧气在不同粒径Pt/C催化剂上的电催化还原

在甲醇溶剂中,利用SnCl₂作为还原剂,通过控制反应条件制备了带有不同粒径Pt粒子Pt/C催化剂。X-射线衍射和透射电镜的研究表明获得的Pt/C催化剂中Pt粒子具有高度的均一性和良好的分散度。电化学研究显示,对于氧气的电催化还原,Pt/C催化剂存在着明显的粒径效应。当Pt粒子粒径为3.2nm时,Pt/C催化剂对氧气的电催化还原的质量比活性最佳。Pt/C催化剂对氧气的粒径效应可能与其表面含氧基团含量、Pt粒子的比表面积及其晶面结构相关。     

氧气在不同粒径Pt/C催化剂上的电催化还原

在甲醇溶剂中,利用SnCl2作为还原剂,通过控制反应条件制备了带有不同粒径Pt粒子Pt/C催化剂。X-射线衍射和透射电镜的研究表明获得的Pt/C催化剂中Pt粒子具有高度的均一性和良好的分散度。电化学研究显示,对于氧气的电催化还原,Pt/C催化剂存在着明显的粒径效应。当Pt粒子粒径为3.2 nm时,Pt/C催化剂对氧气的电催化还原的质量比活性最佳。Pt/C催化剂对氧气的粒径效应可能与其表面含氧基团含量、Pt粒子的比表面积及其晶面结构相关。     

Photocatalytic Reaction of Sulfur Dioxide with Heptane in the Gas-phase Over Titanium Dioxide

IntroductionA broad range of orgainc compounds[1 ,2 ]can be oxidized by means of semiconductor pho-tocatalysis with a primary focus on Ti O2 as a durable photocatalyst in recent years.WhenTi O2 is illuminated with the light of energy greater than the semiconductor band gap,elec-tron- hole pairs(e-- h ) are formed in the conduction and thevalence bandsof thesemiconduc-tor,respectively.These charge carriers,which migrate to the semiconductor surface,are ca-pable of activating oxygen species,et…     

Highly-Branched Palladium Nanodandelions: Simple,Fast, and Green Fabrication with Superior Oxygen Reduction Property

Controllable synthesis of highly-branched metallic structures is of great interest and broad significance for their unique properties of superior conductivity, high porosity, low density, etc., that promote the development of high-efficiency electrocatalysts. Herein, a simple, rapid and green method for the synthesis of highly-branched palladium nanodandelions with flexible ultrafine tentacles and bumpy superficial atomic steps is investigated, without the demand of elevated temperature, seed, template, prolonged reaction time and any organically toxic reducing agent from previously reported highly-branched nanostructures. For the first time, N,N′-methylenebisacrylamide (MBAA) serves as the only additive to simultaneously cover the functions of coordinating agent, reducing agent, and structure-directing agent, facilitating the strategy of intramolecular coordination and self-reduction. Derived from their plentiful ultrafine tentacles, porosity due to the highly-branched structure, and abundant surface atom steps, the Pd nanodandelions exhibit a more positive half-wave of 0.863 V (vs. RHE), optimized specific kinetic activity of 3.0 mA cm⁻² at 0.9 V, and better cycle stability with a maintenance of 77.8 % after 20000 s for the oxygen reduction reaction (ORR), when compared to commercial Pd black. The architectural design of highly-branched metallic structures, as well as the smart fabrication strategy, may hold great promise for exploring a variety of functional nanomaterials.     

乙烷部分氧化超细Fe－Mo－O催化剂的研究

采用溶胶-凝胶法制备了Fe－Mo－O催化剂，用XRD、TEM、BET、IR、TPR、TPD和微反等技术研究了催化剂晶体结构、表面构造、晶格氧活泼性、化学吸附和乙烷部分氧化反应性能。Fe－Mo－O复合氧化物催化剂是由超细微粒组成，微粒粒径约10 nm～20 nm，比表面积为48.1 m2/g。催化剂表面由Lewis碱位（Mo=O键的端氧和Fe－O－Mo键中的桥氧）及Lewis酸位构成。乙烷能以甲基中的H原子吸附在催化剂表面Lewis碱位Mo=O的端氧上形成分子吸附态，其部分氧化产物主要是C2H4和少量的CH3CHO。     

MOF-Mediated Fabrication of a Porous 3D Superstructure of Carbon Nanosheets Decorated with Ultrafine Cobalt Phosphide Nanoparticles for Efficient Electrocatalysis and Zinc–Air Batteries

Superstructures have attracted great interest owing to their potential applications. Herein, we report the first scalable preparation of a porous nickel-foam-templated superstructure of carbon nanosheets decorated with ultrafine cobalt phosphide nanoparticles. Uniform two-dimensional (2D) Co-metal organic framework (MOF) nanosheets (Co-MNS) grow on nickel foam, followed by a MOF-mediated tandem (carbonization/phosphidation) pyrolysis. The resulting superstructure has a porous 3D interconnected network with well-arranged 2D carbon nanosheets on it, in which ultrafine cobalt phosphide nanoparticles are tightly immobilized. A single piece of this superstructure can be directly used as a self-supported electrode for electrocatalysis without any binders. This “one-piece” porous superstructure with excellent mass transport and electron transport properties, and catalytically active cobalt phosphide nanoparticles with ultrasmall size (3–4 nm), shows excellent trifunctional electrocatalytic activities for oxygen evolution reaction (OER), hydrogen evolution reaction (HER), and oxygen reduction reaction (ORR), achieving great performances in water splitting and Zn–air batteries.     

气相合成SnO2超微粒薄膜研究

用直流气体放电活化反应蒸发法在玻璃基片上沉积的SnO2超微粒薄膜,研究其过程中各工艺参数对薄膜结构的影响及作用机理.结果表明, SnO2超微粒薄膜粒径随氧分压增加而增大;蒸镀时间的延长有助于SnO2的生成,也使薄膜发生晶化;而增加放电电压,则薄膜出现外延单晶生长趋势.     

Achieving Superior Electrocatalytic Performance by Surface Copper Vacancy Defects during Electrochemical Etching Process

Vacancy defects of catalysts have been extensively studied and proven to be beneficial to various electrocatalytic reactions. Herein, an ultra‐stable three‐dimensional PtCu nanowire network (NNW) with ultrafine size, self‐supporting rigid structure, and Cu vacancy defects has been developed. The vacancy defect‐rich PtCu NNW exhibits an outstanding performance for the oxygen reduction reaction (ORR), with a mass activity 14.1 times higher than for the commercial Pt/C catalyst (20 %.wt, JM), which is currently the best performance. The mass activity of the PtCu NNW for methanol oxidation reaction (MOR) is 17.8 times higher than for the commercial Pt/C catalyst. Density‐functional theory (DFT) calculations indicate that the introduction of Cu vacancies enhances the adsorption capacity of Pt atoms to the HO* intermediate and simultaneously weakens the adsorption for the O* intermediate. This work presents a facile strategy to assemble efficient electrocatalysts with abundant vacancy defects, at the same time, provides an insight into the ORR mechanism in acidic solution.