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过渡金属氮化物催化性能研究进展 总被引:1,自引:0,他引:1
过渡金属氮化物具有类似于Pt族贵金属的催化性能得到了广泛的研究.综述了过渡金属氮化钼及助剂促进的氮化钼在加氢脱硫与脱氮、氨合成与分解、芳烃加氢和其他涉氢反应(如炔烃、烯烃加氢、丙酮缩合、肼的分解)中的应用,并介绍了其他金属氮化物(如氮化钒、氮化钴)在催化反应中的应用. 相似文献
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以尿素和乙酰丙酮氧钒为原料制备了钒氧化合物络合在纳米薄片石墨化氮化碳上的光催化剂(VO@g?C3N4-T),并与石墨化氮化碳(g?C3N4)、钒氧化合物负载在石墨化氮化碳上催化剂(VO/g?C3N4)进行了对比。采用N2吸附、X射线衍射光谱(XRD)、扫描电镜(SEM)、能谱(EDS)、电感耦合等离子体-原子发射光谱(ICP-AES)分析手段对制备的催化剂进行了表征。考察了所得催化剂可见光催化苯羟基化制 苯酚的性能。结果表明,高比表面积、纳米薄片状的VO@g?C3N4-T催化剂具有合适的带差,导致可见光催化苯的C-H键活化及羟基化具有较好的催化性能,转化率和选择性可以达到98.4%、91.1%。由于石墨化氮化碳和钒具有较强的相互作用,这减少了钒的溶脱,所以该催化剂具有很好的可重复使用性,连续使用五次后,苯的转化率和苯酚的选择性没有明显降低。 相似文献
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研究了微波强化作用下二硫代氨基甲酸盐NS系列化合物对新疆重质原油的脱镍钒效果.合成了具有—CSS—配位基团的NS系列化合物,该系列产物分子结构中—CSS—配位基团,可以与原油中的镍和钒发生配位反应形成水溶性化合物从而从原油中脱除.对于原油脱镍钒效果为NS3 >NS2 >NS4 >NS1,在微波强化作用下NS3脱镍钒剂对原油脱镍钒的实验表明,NS3加入量为200mg/L,微波时间为3min,微波功率为700W,反应温度为90℃和反应时间为20min的条件下,原油中镍和钒的脱除率分别为79.8%和82.4%,微波强化作用后原油的脱镍钒效率增加. 相似文献
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玻璃电熔具有节能、减排、高热效率等优点,正以全电熔和电辅助加热用于玻璃熔窑。钼是广泛用做玻璃电熔窑的电极材料,易还原的元素将严重腐蚀钼电极。二氧化锡陶瓷具有氧化气氛使用、抗玻璃侵蚀能力强的特点,适用于含Pb、As、Sb、F等玻璃。二氧化锡电极的基础系统是SnO2-Sb2O3-CuO。广州市岭南耐火材料有限公司生产二氧化锡电极的技术进步包括:减少或去除CuO以降低对玻璃的污染;双重或多重掺杂施主杂质以增加导电率;引入高熔点氧化物以降低升华、改善高温性能,发展了4种不同类型抗侵蚀性能优越的二氧化锡电极。已用于铅晶质玻璃、高光透过光学玻璃、光伏玻璃和光电子学玻璃。 相似文献
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应用XRD和循环伏安法(CV)对MoO3和Cr2O3混合物与NH3通过程序升温法制得的产物进行表征和测量,结果表明该材料制备的电极具有典型的电容性能。Cr2O3能明显改善电极的性能,掺铬之后,电极的工作电势范围拓宽,比电容增加,可逆性较好。 相似文献
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采用A325树脂对某含钼废水进行吸附,回收废水中的钼并制得了三氧化钼产品。整个过程分为废水中钼的吸附、解吸、除杂净化和三氧化钼的制备等几个步骤。在钼的吸附过程中,当原料液钼浓度2.8g/L时,适宜的工艺条件是:v(料液):v(树脂)=45:1,料液pH值为3.0、料液温度25±2℃、料液流速10mL/min,钼的吸附率可达到94.3%。解吸时,采用10%的氨水溶液作为解吸液,口(解吸液):v(树脂)=2:1进行配料。富钼解吸液再经除杂净化、酸化沉淀、过滤、洗涤、烘干、煅烧,制得三氧化钼产品。 相似文献
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Work has been done on the molten ternary system U-Th-Sn to provide a selective nitriding separation scheme. The nitride formation reaction has been studied as a function of temperature (1490° to 1700°C) and weight percent of U/Th in Sn, using a Sievert's-type apparatus. Nitride formation has been demonstrated in a U-Th-Gd system. 相似文献
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采用恒电位沉积法,将EDOT沉积在玻碳电极表面,对玻碳电极进行修饰,制备修饰电极。利用循环伏安法在电化学工作站上进行对苯二酚的电化学测试,探究pH、扫描速率、待测液浓度等参数来制备最佳修饰电极。 相似文献
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A mathematical model of a positive-negative electrode pair in a lead-acid battery has been developed, and can be solved to determine the potential and current density distribution over the electrode surfaces. With the aid of a computer the model was used to improve the grid design of the positive electrode. The results were compared with those obtained by discharging full-size electrode pairs in a laboratory cell. Agreement between projections and experimental data was about 70% with the assumptions made for certain input parameters. Further development is needed before the model can be applied to the design of radial grids with curvilinear grid members. 相似文献
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S Sadki 《Electrochimica acta》2003,48(6):733-739
Electropolymerization by cyclic voltammetry and chronoamperometry of N-ethylcarbazole (ETCZ) and 3,4-ethylenedioxythiophene (EDOT) was carried out in water-methanol (v/v: 1/3 0.01 M sodium dodecylsulfate (SDS) and 1.25 M perchloric acid on platinum button electrodes. Methanol improves the ethylcarbazole solubility and allows a well defined polymer growth on the working electrode. The SDS makes easier the ETCZ and EDOT electropolymerization. Indeed, the presence of micelles decreases the monomer oxidation potential and induces an acceleration of the polymerization. ETCZ and EDOT have similar monomer oxidation potentials in this medium. Moreover their polymers show a better stability than the polymers obtained without surfactants. Therefore, electropolymerization mixtures of these monomers was carried out with different ratios (v/v, 70/30, 50/50 and 30/70) in order to prepare copolymers and the resulting products were characterized by electrochemistry, IR and UV-visible spectroscopy and SEM. 相似文献
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The purpose of this paper was to evaluate the performance of a modified zeolite as an anticorrosive pigment for paints. A
procedure to prepare the pigment was outlined and its anticorrosive properties assessed following the electrochemical behavior
of a steel electrode in pigment suspension. In a second stage, alkyd paints were formulated employing different anticorrosive
pigments: (1) 30% by volume (v/v) of the modified zeolitic rock, (2) 10% (v/v) of zinc phosphate, and (3) a mixture of 10%
(v/v) zinc phosphate plus 20% (v/v) of the modified zeolitic rock. In every case, percentages were referred to the total pigment
content. Titanium dioxide, zinc oxide, and barium sulfate were incorporated to complete the pigment formula. The pigment volume
concentration/critical pigment volume concentration (PVC/CPVC) ratio was 0.8. The performance of the resulting anticorrosive
paints was assessed by accelerated (salt spray and humidity chambers) tests and electrochemical (corrosion potential, ionic
resistance, and polarization resistance) essays. It was demonstrated that the modified zeolite is effective in protecting
steel from corrosion when it is used in combination with zinc phosphate. There exists a synergism between the modified zeolite
and zinc phosphate that allows the zinc phosphate content in anticorrosive paints to be reduced. 相似文献