微量铂与铑对Co／CeO2催化剂结构与性能的影响

采用等量分步浸渍法先后将Ｃｏ与贵金属组份浸于ＣｅＯ２上，经５００℃焙烧２ｈ，４５０℃氢气还原１ｈ制得Ｃｏ－Ｐｔ／ＣｅＯ２和Ｃｏ－Ｒｈ／ＣｅＯ２催化剂。活性测试结果表明，贵金属与Ｃｏ之间具有催化协同效应。对ＣＯ氧化，Ｐｔ与Ｃｏ的协同效应较显著，而对富氧条件下ＣＨ４选择还原ＮＯ，Ｒｈ与Ｃｏ的协同效应更为明显，ＸＰＳ和ＥＸＡＦＳ结果一致表明，经Ｈ２还原后，样品Ｃｏ／ＣｅＯ２、Ｃｏ－Ｐｔ／ＣｅＯ２和Ｃｏ－     

La—Ce—Mn系钙钛矿型催化剂性能研究

采用共沉淀法制得了Ｃｅ＾４＋，部分取代Ｌａ＾３＋的Ｌａ１－ｘＣｅｘＭｎＯ３钙钛矿型催化剂，实验结果表明，随Ｃｅ＾４＋取代量ｘ的增大，Ｌａ１－ｘＣｅｘＭｎＯ３催化剂越易被还原，其还原活化逐渐降低，对于ＣＯ，ＣＨ４氧化的反应其活性有一最大值，ＣＯ反应ｘ的０．４，ＣＨ４反应ｘ为０．２，这是由于随ｘ值的增大，催化剂晶格缺陷增多，晶格氧的化学势增大，以及ＣｅＯ２杂质相的协同作用的结果，在ＣＯ氧化和用Ｈ２还原     

金属羰基化合物（CpFe（CO）2）2与金属氧化物表面作用的傅里叶变…

用漫反射红外光谱和光声红外光谱研究了金属羰基化合物（ＣｐＦｅ（ＣＯ）２）２Ｃｐ＝η＾５－Ｃ５Ｈ５与酸性，中性和碱性Ａｌ２Ｏ３及ＴｉＯ２的相互作用，结果表明，在Ａｌ２Ｏ３表面生成的洗生物种类及浓度与Ａｌ２Ｏ３的酸碱度明显相关，在酸性Ａｌ２Ｏ３表面，主要存在衍生物（ＣｐＦｅ（ＣＯ）２Ｆｅ－Ｈ－Ｆｅ（ＣＯ２Ｃｐ）＾＋及少量的ＣｐＦｅ（ＣＯ）２（－Ｏ－）；在中性Ａｌ２Ｏ３表面存在的ＣｐＦｅ（ＣＯ）２（－Ｏ     

PdO引入对CuO／γ—Al2O3催化剂结构与性能的影响

运用ＰＴＲ,ＳＥＭ,ＸＲＤ阶梯扫描及ＣＯ和ＣＨ４氧化活性测定表征技术研究了ＣｕＯ／γ－Ａｌ２Ｏ３催化剂及负载ＰｄＯ对催化剂性能的影响。结果表明,ＣｕＯ／γ－Ａｌ２Ｏ３催化剂上引入不同含量的ＰｄＯ,使ＴＰＲ还原峰温欠下降。对载体上ＣｕＯ平均晶粒大小的测定表明随ＰｄＯ含量的增加,ＣｕＯ平均晶粒逐渐减小;ＳＥＭ对ＰｄＯ－ＣｕＯ／γ－Ａｌ２Ｏ３催化剂上Ｃｕ元素分布的面扫描测定亦证实了随ＰｄＯ含量的增加,催     

负载型铁催化剂上费托合成的反应机理

用瞬时应答技术对费托合成的初始态动力学行为进行跟踪，研究了Ｆｅ／γ－Ａｌ２Ｏ３，Ｆｅ－Ｃｏ／γ－ＡＬ２Ｏ３和Ｆｅ－Ｃｏ－Ｋ２Ｏ／γ－Ａｌ２Ｏ３催化剂上ＣＯ氢化生成轻的催化性能和Ｃ２烃的生成机理。结果表明，在Ｆｅ－Ｃｏ－Ｋ２Ｏ／γ－Ａ２Ｏ３上ＣＯ解离吸附形成的表面碳是合成烃反应的活性中心，表面碳的逐步氢化，生成亚甲基物种而亚甲基物种的聚合促成了烃键的增长。     

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。     

La2O3—BaO系复氧化物的现场拉曼光谱研究

对于Ｌａ０．２Ｂａ０．８－ｘＣａｘ（Ｏ，ＣＯ３）其中ｘ＝０．０、０．２、０．４、０．６氧化物在９７３Ｋ及甲烷氧化偶联（ＯＣＭ）条件下，无Ｃａ＾２＋的样品可用表面ＢａＣＯ３和（ＬａＯ）２ＣＯ３的Ｒａｍａｎ谱及８１０ｃｍ＾－１附近的Ｏ２＾２－特征峰来表征；含Ｃａ＾２＋的样品，则表现了混合碳酸盐（Ｃａ，Ｂａ）ＣＯ３的特征，还有位于１１３５ｃｍ＾－１（ｗ）和８１０ｃｍ＾－１（ｗ）的Ｏ２＾－、Ｏ２＾２－瞬时     

微波等离子体处理聚乙烯膜的表面结构分析

以ＥＳＣＡ和ＥＰＭＡ等主手段，探讨并比较了微波场下Ｎ２，Ｈｅ，ＣＯ２，Ｏ２，Ｈ２Ｏ及空气放电产生的等离子体对聚乙烯膜的表面改性与蚀刻作用，结果表明不同的等离子处理均使样品表面引入化学形式相同但含量有所不同的含氧（－Ｃ－Ｏ－，－ＣＯ－Ｏ－）和含氮（－ＮＨ－，－ＮＨ２）极性基团，没有生成羰基（Ｃ＝Ｏ）并使样品受到不同程度的蚀刻，处理后的样品表面亲水性增强，其中以Ｎ２和Ｈｅ等离子体处理的样品亲水性提高较     

四—（对—羟基苯基）卟啉在水／三氟乙酸溶液中J—聚集的光谱研究

本文研究了四－（对－羰基苯基）卟啉（ＴＣＰＰ）在Ｈ２Ｏ／ＣＦ３ＣＯＯＨ、Ｈ２Ｏ／ＣＣＩ３ＣＯＨ和Ｈ２Ｏ／ＣＨ３ＣＯＯＨ溶液中的ＵＶ－Ｖｉｓ吸收光谱、荧光光谱和拉曼光谱。实验表明,ＴＣＰＰ在Ｈ２Ｏ／ＣＨ３ＣＯＯＨ和Ｈ２Ｏ／ＣＣＩ３ＣＯＯＨ溶液中以分子态的Ｎ－质子化卟啉Ｈ８ＴＣＰＰ＾２＋存在,而在Ｈ２Ｏ／ＣＦ３ＣＯＯＨ中则形成Ｈ８ＴＣＰＰ＾２＋的Ｊ－聚集体。Ｊ－聚集体显示,ＵＶ－Ｖｉｓ吸收光谱和荧光光     

光泽精－H_2O_2－KCl中性非缓冲体系电生化学发光行为及机理研究

本文用自制的电生化学发光仪，选择光泽精－Ｈ２Ｏ２－ＫＣｌ中性（非缓冲）水溶液作为电生化学发光（ＥＣＬ）体系。该体系具有比前人所研究的ＬＵＣ－Ｏ２的碱性水溶液的ＥＣＬ体系灵敏度高，ＥＣＬ强度大，还原产物不易沉积在阴极上影响发光及所发的ＥＣＬ不与传统的ＣＬ相混淆的优点。光泽精浓度在８×１０－５～４×１０－８ｍｏｌ．Ｌ－１范围内与ＥＣＬ强度成正比，光泽精检测限为１０－９ｍｏｌ．Ｌ－１。此外还对该体系的测定条件及机理进行了研究，并提出了可能的机理。     

表面合金电催化剂上甲酸氧化的原位FTIR反射光谱研究

运用原位红外反射光谱(FTIRS)和电化学循环伏安法(CV)研究了甲酸在三种不同电极上的电催化特性。结果表明甲酸在碳载铂电极(Pt/GC)上的电催化氧化机理与本体铂电极(Pt)相类似,即可以通过活性中间体或毒性中间体氧化至CO_2。Pt/GC对甲酸的氧化比Pt具有更高的电催化活性。Pt/GC表面以Sb吸附原子修饰的电极(Sb-Pt/GC)上,甲酸氧化的起始电位(E;)提前至-0.10V,氧化电流峰电位(Ep)提前至0.34V,氧化峰电流(jp)值增加了7.28倍,半峰宽(FWHM)为0.30V。同样,Surface al-loy/GC电极上,E_I为-0.12V,E_p为0.32V和j_p为7.25mA·cm~(-2),相对Pt/GC分别负移了0.22,0.02V和增大了8.15倍,半峰宽(FWHM)为0.5V。表明Sb-Pt/GC和Surface alloy/GC电极不仅能够有效地抑制毒性中间体CO的生成,而且还可以显著地提高其对活性中间体的氧化的电催化活性。     

碱性介质中纳米薄膜Ru电极上CO吸附的异常红外效应

研制纳米级厚度的Ｒｕ薄膜电极,并运用电化学原位ＦＴＩＲ反射光谱研究碱性介质中ＣＯ的吸附。检测到ＣＯ以线型吸附态为主,但也存在少量桥式吸附态,分别在１９６０和１７８０ｃｍ＾－１附近红出红外吸收谱峰。发现纳米Ｒｕ膜电极具有异常红外效应,即ＣＯ谱峰方向倒反,强度增强和半峰宽增加,测得在碱性溶液中吸附态ＣＯ的红外吸收被增强了３３倍,其增强因子是酸性溶液中的两倍左右。     

Oxygen reduction activity of N-doped carbon-based films prepared by pulsed laser deposition

Carbon-based films with nitrogen species on their surface were prepared on a glassy carbon (GC) substrate for application as a non-platinum cathode catalyst for polymer electrolyte fuel cells. Cobalt and carbon were deposited in the presence of N₂ gas using a pulsed laser deposition method and then the metal Co was removed by HCl-washing treatment. Oxygen reduction reaction (ORR) activity was electrochemically determined using a rotating disk electrode system in which the film samples on the GC substrate were replaceable. The ORR activity increased with the temperature of the GC substrate during deposition. A carbon-based film prepared at 600 °C in the presence of N₂ at 66.7 Pa showed the highest ORR activity among the tested samples (0.66 V vs. NHE). This film was composed of amorphous carbons doped with pyridine type nitrogen atoms on its surface.     

Sb和S修饰Pt电极上1,3 -丁二醇氧化的原位红外反射光谱研究

运用电化学原位ＦＴＩＲ反射光谱研究了１,３－丁二醇在以Ｓｂ和Ｓ修饰的Ｐｔ电极上的氧化过程。结果表明Ｓｂ和Ｓ修饰都能抑制１,３丁醇的解离吸附。红外数据指出Ｓｂ的存在使１,３丁二醇氧化产物同时含有羰基物种和ＣＯ２,而Ｓ修饰的Ｐｔ电极上以羧酸物种为主。     

Ultrasound-boosted selectivity of CO in CO2 electrochemical reduction

Among the possible products of CO₂ electrochemical reduction, CO plays a unique and vital role, which can be an ideal feedstock for further reduction to C₂₊ products, and also the important component of syngas that can be used as feedstock for value-added chemicals and fuels. However, it is still a challenge to tune the CO selectivity on Cu electrode. Here we newly construct an ultrasound-assisted electrochemical method for CO₂ reduction, which can tune the selectivity of CO₂ to CO from less than 10% to >80% at −1.18 V versus (vs.) reversible hydrogen electrode (RHE). The partial current density of CO production is significantly improved by 15 times. By in-situ Raman study, the dominating factor for the improved CO production is attributed to the accelerated desorption of *CO intermediate. This work provides a facile method to tune the product selectivity in CO₂ electrochemical reduction.     

碱性溶液中纳米钯膜电极表面CO、CN-吸附的红外反射光谱研究

以原位ＦＴＩＲ反射光谱研究碱性介质中ＣＯ和ＣＮ＾－在纳米Ｐｄ膜电极上的吸附和共吸附,进一步揭示了纳米薄膜材料的异常红外效应和ＣＯ与ＣＮ＾－共吸附时的相互作用规律。     

碱性介质中正丁醇在铂电极上吸附和氧化的电化学原位FTIR反射光谱和EQCM研究

运用电化学循环伏安(CV)、原位FTIR反射光谱和电化学石英晶体微天平(EQCM)等方法研究了碱性介质中正丁醇在Pt电极表面吸附和氧化行为。结果表明：正丁醇电氧化过程与溶液酸碱性有着密切的关系。酸性介质中正丁醇在Pt电极上的CV曲线有2个正向氧化峰,而碱性介质中只有1个正向氧化峰, 第2个氧化峰的消失可能是由于碱性介质中Pt电极表面钝化引起的。原位FTIR反射光谱检测到,在实验条件下,碱性介质中正丁醇电氧化过程的最终产物只有丁酸根。EQCM研究还从电极表面质量定量变化的角度提供了正丁醇反应机理的新数据。     

In situ synchrotron far infrared micro-spectroelectrochemistry with a grazing angle objective

We demonstrate the use of a grazing angle objective attachment to carry out in situ far infrared micro-spectroelectrochemistry at a copper electrode on a nano-scale. A thin-layer spectrochemical cell made out of Teflon was used, fitted with a 20-μm thick Mylar window; the working electrode was 500 μm in diameter. Measurements were carried out in 0.1 M NaOH solution as a function of applied potential between –1.4 and 0 V vs a Hg/Hg₂SO₄ reference electrode. Spectra were obtained with excellent signal to noise ratio for the surface oxide film, formed on copper electrochemically with less than 1 nL of active solution volume. The surface film at 0 V was about 130 nm thick and consisted mainly of CuO, with possibly some Cu(OH)₂ also present. This interpretation is consistent with previous works and thermodynamic calculations. The technique should be useful in other investigations and the further development of electrochemical surface science.     

Nanostructured copper particles-incorporated Nafion-modified electrode for oxygen reduction

The electrocatalytic activity of nanostructured copper particles (represented as Cu_nano) incorporated Nafion (Nf) film-coated glassy carbon (GC) electrode (GC/Nf/Cu_nano) towards oxygen reduction was investigated in oxygenated 0.1 M phosphate buffer (pH 7.2). The electrodeposited Cu_nano in Nf film was characterized by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The electrocatalytic activity of Cu_nano at the modified electrode towards oxygen reduction was studied using cyclic voltammetry technique. The molecular oxygen reduction at the GC/Nf/Cu_nano-modified electrode started at a more positive potential than at a bare GC electrode. A possible reaction mechanism was proposed in which oxygen reduction may proceed through two-step two-electron processes at the GC/Nf/Cu_nano electrode. The GC/Nf/Cunano electrode shows higher stability for oxygen reduction in neutral solution and the electrode may find applications in fuel cells.     

Crystalline Sb–Cu alloy films as anode materials for Li-ion rechargeable batteries

A crystalline Sb–Cu alloy is investigated for use in Li-ion rechargeable batteries, and its structural, electrochemical and thermal properties are characterized. A pulse electrodeposition method is used to prepare Sb–Cu alloy film on Cu foil as a negative electrode. The structure of the alloy film electrode is characterized using XRD, FE-SEM and EDX. The electrochemical behavior of the Sb–Cu alloy film is investigated at the current rate of 0.1C to the cut-off potential range of 1.8 and 0.01 V vs. Li/Li⁺. Our experimental results demonstrate that the initial discharge capacity is 850 mAh g^?1 and that the discharge capacity increases to 1034 mAh g^?1 at the end of the 30th cycle with a stable cycle life. The Coulombic efficiency is approximately 83.5% with good cyclability. Moreover, the crystalline Sb–Cu alloy film has relatively low exothermic properties, and it may be an interesting candidate for use in the negative electrodes of Li-ion batteries.