A new way to increase performance of oxide electrode for oxygen reduction using grain growth inhibitor

Nickel oxide was introduced as a grain growth inhibitor into Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3 − δ (BSCF) electrode to increase its activity for oxygen reduction reaction. Small amount of NiO can effectively suppress the grain growth of BSCF by spinning the grain boundary and thus increase the electrode surface area, while the particle connection is not obviously affected. Electrochemical impedance spectra of symmetric cells indicate that the electrode activity for oxygen reduction is indeed effectively improved by introducing NiO additive. At 600 °C, area specific resistance of BSCF+5wt.% NiO is about 36.5% lower than that of pure BSCF electrode. Single cell tests also demonstrate an improved cell power output by introducing NiO additive. It implies that the adoption of a sintering inhibitor may be a facile and practical way to increase electrode activity for oxygen reduction.     

Heterogeneously catalyzed synthesis of primary amides directly from primary alcohols and aqueous ammonia

In the presence of a manganese oxide based octahedral molecular sieve (OMS-2), a range of primary amides could be synthesized directly from primary alcohols and ammonia. The observed catalysis was heterogeneous, and the recovered catalyst could be reused many times without an appreciable loss of its catalytic performance.     

STUDY ON TPR OF NICKEL OXIDE CATALYSTS CALCINED AT HIGH TEMPERATURES

TPR technique has been used, to investigate the reducibilities of three types of nickel oxide catalysts calcined in air between 650℃and 1050℃: NiO/Al2O3, NiO/MgAl2O4and NiO/(CaO, MgO) · A12O3· xSiO2. The results indicate that the TPR peaks of all the catalysts were shifted toward high temperature and peak areas were gradually reduced with increasing calcination temperature. Particularly, the main TPR peaks almost disappeared at 1050℃-It was also observed that NiO/(CaO, MgO)· Al2O3 · xSiO2 catalyst was the easiest to be reduced of these catalysts, and there was a small shoulder peak before the main peak for each catalyst. Examination of these catalysts by XPS showed that there were two forms of nickel oxides on support surface .     

SYNTHESIS OF DBN AND ITS CATALYTIC PERFORMANCE FOR METHANOL CARBONYLATION TO METHYL FORMATE

1 , 5-diazabicyclo['1, 3, 0]non-5-ene(DBN) has been synthesized in our laboratory, and its catalytic activity and selectivity for methanol carbonylation to methyl formate (MF) have been studied. The experimental results have demonstrated that the synthetic processes of DBN used for the present work are reasonable and feasible. The total yield of three steps of DBN synthsis is approximate to 80%. The activity evaluation has shown that DBN can effectively catalyze the carbonylation reaction of methanol in the presence of propylene oxide (PO) promoter. PO-promoted DBN is a novel catalytic system superior to sodium methoxide.     

SOLID STATE CHEMISTRY OF La_(1-x)Li_(x)MnO_3 AND RELATED COMPOUND

A series of perovskite type oxides La_(1-x)A_(x)MnO_3(x=0.1 for A=Li,Na,K;x=0.1～0.5 for A=Li)have been prepared by impregnation.Experimental results showed that the substitution of La~(3 ) by Li~ inLaMnO_(3 ?) greatly increased the selectivity to ethane and ethylene for theoxidative coupling of methane.Temperature-programmed desorption of oxygenproved the presence of oxygen vacancies in the oxide lattice.The higher Mn~(4 )/Mn_t ratio in oxide made the formation of oxygen vacancies easier on the oxidesurface.The general formula of the oxides is La_(1-x)Li_(x)Mn＇V＇_(y)O_(3-y),V=vacancy.     

CHARACTERIZATION OF AMPHIPHILIC AND MICROPHASE SEPARATED GRAFT COPOLYMERS Ⅱ SURFACE CHARACTERIZATION AND IN VITRO BLOOD-COMPATIBILITY ASSESSMENT OF POLYSTYRENE-GRAFT-ω-STEARYLPOLY (ETHYLENE OXIDE)*

This paper reported the research results concerning the surface characterization ofpolystyrene-graft-w-stearyl poly(ethylene oxide) (PS-g-SPEO) by means of XPS,contactangle measurement and TEM, and its in vitro blood compatibility assessment by measuringthe plasma recalcification time (RT) and partial thromboplastin time (PTT). The XPSresults demonstrated that the surface and bulk composition of the PS-g-SPEO graftcopolymers differ remarkably from each other,and that SPEO component was constantlyenriched at the copolymer/air interface. Contact angle studies indicated that the surfacewater wettability can be adjusted effectively by changing the composition of the copolymer.PS-g-SPEO graft copolymers can undergo microphase separation as clearly illustrated byTEM photographs. The relationship between the surface properties of PS-g-SPEO graftcopolymer and its blood compatibility was also discussed.     

聚苯醚磺酸锂与聚醋酸乙烯酯共混物的导电性能研究

为改善聚苯醚磺酸锂（SPPOLi）的导电性能，将聚酷酸乙烯酯（PVAc）与之共混，X-射线衍射分析表明，PVAc可降低SPPOLi凝聚结构的有序程度；发现共混后电导率有了较大提高，共混物的电导对温度的依赖关系不符合阿仑尼马斯方程；同时，共混物仍保持了单离子传导性．     

ICP－AES法测定氧化铕中14种数量稀土杂质

采用ＩＣＰ－ＡＥＳ单道扫描光谱仪详细考察了十四种被测稀土杂质元素的４７条灵敏分析线的谱线轮廓及基体Ｅｕ的背景谱线轮廓，从而选定基体干扰小，灵敏度高的分析线及扣除背景的合适位置；试验了酸度，载气流量，观测高度，射频发生器功率等对信号强度和基体干扰程度的影响，采用基体匹配法校正基体对测定的影响，建立了氧化铕中１４种稀土杂质的直接测定法。已用于出口产品的分析和标准试样的定值测定，得到了满意的结果。     

甲苯气相选择性氧化制苯甲醛 Ⅰ．V_2O_5／TiO_2－Al_2O_3催化剂研究

制备了一系列负载型Ｖ－Ｔｉ－Ａｌ－Ｏ催化剂并用于甲苯的气相选择性氧化制苯甲醛，考察了接触时间、氧浓度、Ｖ２Ｏ５负载量以及催化剂焙烧温度对反应性能的影响。用ＴＰＲ、ＸＲＤ和ＢＥＴ等测试手段，对催化剂进行了表征。研究发现，催化剂在７７３Ｋ时活化，接触时间１．２秒，氧浓度２１％时，可获得较好的反应结果，Ｖ２Ｏ５负载量为６（ｗｔ）％的催化剂，在５９３Ｋ时反应，得到了转化率２０．５％，苯甲醛产率８．３％的最好结果。