两段碳还原MoO3反应产物的成分研究

采用石墨粉为碳源分两段还原MoO3粉末,通过对各阶段产物的XRD、FESEM和EDS分析表征,初步探讨还原过程中可能的反应历程。结果表明,Mo4O11可能是碳还原MoO3为MoO2过程中的过渡相;经650℃和1 250℃各还原1h后,MoO3粉末可被碳较充分地还原成结晶度较高、粒径均匀的金属钼粉,且产物中存在少量的副产物α-Mo2C。     

共沉淀法制备铬酸钬粉体及铬酸钬气敏元件的气敏性能

采用共沉淀法制备HoCrO3前驱体,将前驱体在不同条件下热处理得到铬酸钬纳米粉体。利用X射线衍射仪和扫描电子显微镜对HoCrO3纳米粉体的晶体结构和微观形貌进行了表征,对用HoCrO3纳米粉制作的元件进行气敏性能测试,研究了热处理条件对HoCrO3气敏元件气敏性能的影响。结果表明：所制备的HoCrO3粉体为纳米颗粒,平均粒径约为50nm,属于钙钛矿型复合氧化物;采用800℃保温2h制备的HoCrO3气敏元件对三甲胺气体具有较高的灵敏度、良好的选择性和稳定性;样品的检测限较低,对体积分数为1×10^-7三甲胺的灵敏度为3。HoCrO3是检测三甲胺的一种很有应用前景的半导体气敏材料。     

Acetic acid gas sensors based on Ni~(2+) doped ZnO nanorods prepared by using the solvothermal method

正Ni~(2+)-doped ZnO nanorods with different doping concentrations are prepared via the solvothermal method.The doped ZnO nanorods are characterized by X-ray diffraction(XRD) and scanning electron microscopy (SEM),respectively.The amount of Ni~(2+) ions that enter the lattice of ZnO increases with increasing the Ni~(2+)/Zn~(2+) molar ratio when the molar ratio of Ni~(2+)/Zn~(2+) in the starting solution is lower than 3%and does not change obviously if the mole ratio of Ni~(2+)/Zn~(2+) in the starting solution is in the range of 3-10 mol%.The effect of Ni~(2+) doping on the gas-sensing properties is investigated.The results reveal that the amount of Ni~(2+) has a great influence on the response(R_a/R_g) and the gas-sensing selectivity.The sensor based on 1 mol%Ni~(2+) doped ZnO nanorods (120℃,10 h) exhibits a high response to acetic acid vapor,in particular,the responses to 0.001 ppm and 0.01 ppm acetic acid vapor reach 1.6 and 2,respectively.The response time and the recovery time for 0.001 ppm acetic acid are only 4 s and 27 s,respectively.     

Preparation and Performance of Sm1-xCaxCrO3-δ as New Interconnect Materials for IT-SOFC

为了探索适用于中温固体氧化物燃料电池的连接材料,采用柠檬酸法制备了Sm1-xCaxCrO3-δ(x=0,0.1,0.2,0.3,0.4)粉体,研究了Ca2+掺杂对材料烧结性能、电性能和热膨胀性能等的影响。实验结果表明,Sm0.7Ca0.3CrO3-δ材料在空气中700℃时电导率为29.8 S·cm-1,氢气气氛中600°C时为1.68 S·cm-1。在30~1000℃温度范围内随着Ca2+掺杂量从0.1增加到0.4,平均热膨胀系数(TECs)值从7.34×10–6增大到8.05×10-6 K-1,与其它常用固体氧化物燃料电池材料热匹配性良好。     

CT-1复合促进剂对常温铁系磷化液性能的影响

以钛盐为主要原料,研制了CT-1复合促进剂,考察了游离酸度(FA)、总酸度(TA)以及CT-1复合促进剂对常温铁系磷化液性能的影响,用IR对磷化膜的主要成分进行了表征.结果表明:适量CT-1促进剂可以提高磷化膜的致密性和耐蚀性,膜的成分以缔和型磷酸盐为主.     

NdFeO3 as anode material for S/O2 solid oxide fuel cells

Sulfur-oxygen solid oxide fuel cells (S/O2-SOFCs) can improve the utilization ratio of energy via converting the combustion heat of sulfur into electrical energy directly, and sulfur trioxide which is an intermediate in sulfuric acid industry can be obtained directly via S/O2-SOFCs. The anode material NdFeO3 was prepared via sol-gel method, the phase stability of NdFeO3 in sulfur vapor or sulfur dioxide atmosphere was investigated. The single cell, consisting of NdFeO3-SDC/SDC/LSM-SDC structure, was fabricated by the screen-printing method and tested by the home-built equipment with sulfur vapor or sulfur dioxide as the fuel. As indicated by X-ray diffraction (XRD) analysis, NdFeO3 was stable in sulfur vapor or sulfur dioxide atmosphere at 800℃, the phase composition of the mixture of NdFeO3 and SDC (Sm doped CeO2) did not change after the mixture was calcined at 800℃ for 4 h. The transmission electron microscope (TEM) photograph revealed that the average grain size of NdFeO3 powder was about 80 nm. With sulfur vapor or SO2 as the fuel, the maximum open circuit voltages (OCVs) of the single cell were 409 mV at 620℃ and 474 mV at 650℃, respectively; the maximum power densities of single cell were 0.154 mW/cm2 at 620℃ and 0.265 mW/cm2 at 650℃, respectively.     

酒石酸铁（Ⅲ）催化H_2O_2分解反应动力学研究

本文确定了酒石酸铁（Ⅲ）催化分解Ｈ_２Ｏ_２反应在ｐＨ＝２．００－４．６０范围内及温度为２９１Ｋ时的速率方程，结果表明：反应速率与ｐＨ呈＂∧＂型相关性。酒石酸氢铁（Ⅲ）是该反应主要活性催化物，并具有过氧化氢酶模式。     

预辐照辐射接枝反应的研究 2.甲基丙烯酸辐射接枝于聚三氟氯乙烯薄膜

甲基丙烯酸由于它在α碳原子上有着甲基,因而强氧化剂存在时比丙烯酸有更好的化学稳定性。我们研究了甲基丙烯酸辐射接枝于聚三氟氯乙烯薄膜,以制备具有良好抗氧化性性能的羧酸型离子交换膜。丙烯酸辐射接枝于聚三氟氯乙烯已有报道,而甲基丙烯酸预辐照辐射接枝于聚三氟氯乙烯的研究尚未见报道。本工作研究了甲基丙烯酸、甲基丙烯     

Cu2+掺杂ZnO纳米棒的制备及气敏性能研究

通过溶剂热法(无水乙醇)制备了Cu2+(0～6mol%)掺杂ZnO纳米棒粉体,采用X射线衍射仪和扫描电镜对掺杂ZnO纳米粉体的晶体结构和微观形貌进行了表征.研究了Cu2+掺杂比例、溶剂热反应温度及时间对材料气敏性能的影响;考察ZnO(120℃,10h)和3mol%Cu2+掺杂ZnO(120℃,10h)粉体对应元件对甲醛、乙酸、甲苯、乙醇、丙酮、三甲胺等六种气体的气敏性能.结果表明:通过溶剂热法制备的ZnO粉体为纳米棒状结构,棒长度和直径随Cu2+掺杂比例不同发生变化;3mol%Cu2+掺杂ZnO(120℃,10h)样品对应元件对低浓度乙醇有很好的选择性,在395℃工作温度下对1×10–3乙醇的灵敏度为380.5,响应和脱附时间分别为5 s和40 s,对1×10–6乙醇的灵敏度可达4.2.     

SOFC连接材料Nd_(1-x)Ca_xCrO_(3-δ)的制备及性能研究

为了探索适用于中温固体氧化物燃料电池的连接材料,采用柠檬酸法制备了Nd1-x Ca x CrO3-δ(x=0,0.1,0.2,0.3,0.4)粉体,研究了Ca2+的掺杂对材料烧结性能、电性能和热膨胀性能等的影响。实验表明,当测试温度为800℃时,Nd0.6Ca0.4CrO3-δ材料在空气和氢气气氛中电导率分别为56.4和1.6 S/cm。在30~800℃随着Ca2+掺杂量从0.1增加到0.4,平均热膨胀系数(TECs)值从6.5×10-6K-1增大到7.8×10-6K-1,与其它常用SOFC材料热匹配性良好。