【作者】 王东；

【导师】 刘春明； 王常珍；

【作者基本信息】 东北大学 ， 材料学， 2009， 博士

【摘要】 自八十年代初期,掺杂Yb3+的SrCeO3被发现在高温含氢或水蒸气气氛中表现出良好的质子传导性以来,钙钛矿型质子导体在固体氧化物燃料电池、气体传感器、氢泵、水蒸气电解制氢、有机化合物的加氢和脱氢、常压合成氨等电化学装置日益显示重要的应用价值和广阔的应用前景,引起了世界各国专家学者的广泛关注。本论文综述了钙钛矿型质子导体的晶体结构、质子的形成、传导机理和应用前景,并按照化学成分分类讨论其电学性质的特点；介绍了常用的钙钛矿型质子导体的制备和表征方法；讨论了制备过程中的原料球磨时间对BaCe0.90Y0.10O3-α和Ba3Ca1.18Nb1.82O9-δ的粉体粒度、晶体结构、微观形貌及导电性能的影响；尝试采用热压铸方法来成型CaZr0.9In0.1O3-α管,摸索出一套合理的工艺参数,并对CaZr0.9In0.1O3-α的性质进行了表征；概述了目前国内外铝和铝合金熔体的测氢和脱氢技术现状,分别以CaZr0.9In0.1O3-α、BaCe0.90Y0.10O3-α、BaCe0.85Y0.15O3-α和BaCe0.90Sm0.10O3-α为电解质制作电化学氢泵,以CaZr0.9In0.1O3-α为电解质制作氢传感器,运用电化学方法对铝熔体进行了脱氢和测氢研究；总结全文,提出了钙钛矿型质子导体进一步研究的发展方向。通过实验和分析所取得的主要研究结果为：(1)适度延长原料球磨时间,原料颗粒得到进一步细化,不仅能降低BaCe0.90Y0.10O3-α或Ba3Ca1.18Nb1.82O9-δ的合成温度,还能使合成粉体保持粒度小、分布窄和比表面积大的特性,其烧结样品的致密度和导电性能也得到相应提高。(2) BaCe0.90Sm0.10O3-α、BaCe0.90Y0.10O3-α和BaCe0.85Y0.15O3-α质子导体在空气中573～873K内的电导率依次提高,电导激活能依次降低,表明提高Y元素的掺杂含量或掺杂与Ce4+离子半径接近的小半径离子有利于改善BaCeO3基材料的电学性质。(3)一套合理的热压铸成型CaZr0.9In0.1O3-α管的工艺参数为：压力0.5MPa,持续时间15s,模具温度30℃,蜡浆温度73℃,蜡浆成分配比粉体：石蜡：蜂蜡：油酸=87.8%：11%：1%：0.2%,排蜡温度1000℃。CaZr0.9In0.1O3-α烧结样品中In含量降低,是由于样品在烧结过程中分解出少量的In2O3离解为InO+O2, InO升华造成的。(4)由CaZr0.9In0.1O3-α作电解质制作电化学氢泵分别在真空抽取、气体携带和外加电压条件下对铝液进行脱氢。结果表明,外加电压1.5V时的脱氢速度最快,其次为真空抽取法。气体携带法的脱氢效率相对较低,而氧气的携带效果相对好于氩气携带。(5)由BaCe0.90Y0.10O3-α、BaCe0.85Y0.15O3-α和BaCe0.90Sm0.10O3-α作电解质分别制作的电化学氢泵,在铝液温度760℃、780℃和800℃,铝液上方的水蒸气分压4122.8Pa～4754.7Pa,外加电压0.4V、0.8V和1.2V时对铝熔体进行脱氢。结果表明,氢泵中的电流随铝液温度的升高,铝液上方水蒸气分压的增加和外加电压的增大而增大。(6)制备了一种新型的参比电极材料YH0.55+YH0.9,并用于CaZr0.9In0.1O3-α作电解质的铝液测氢传感器中,传感器的响应时间约20s。更多还原

【Abstract】 Since it was reported that SrCeO3 doped Yb3+ion showed good protonic conduction under atmosphere containing hydrogen or steam at high temperature in early 1980’s, the applications of perovskite-type proton conductors on electrochemical devices such as solid oxide fuel cells, gas sensors, hydrogen pump, steam electrolyzer for hydrogen production, hydrogenation and dehydrogenation of organic compound have exihibited very important values and wide prospect and attracted extensive attention all over the world.In this paper, we reviewed crystal structure, forming of proton, conduction mechanism and application prospect of perovskite-type proton conductors, and characteristics of perovskite-type proton conductors were classified and discussed according to their chemical constituents (1 st Chapter). And then the common preparation and characterization methods of perovskite-type proton conductors were introduced (2nd Chapter); The influence of milling time for original mixture during the preparation process on partical size distribution, crystal structure, micro-topography and electrical property of BaCe0.90Y0.10O3-αand Ba3Ca1.18Nb1.82O9-δpowders and sintered samples were discussed (3rd,5th Chapter); This paper attempts to form CaZr0.9In0.1O3-αtubes by hot pressure casting. And a set of reasonable process parameters were found. Meanwhile, properties of CaZr0.9In0.1O3-αproton conductor were characterized (4th Chapter). The present situation about dehydrogenation and detection of hydrogen in molten aluminium and aluminium alloy was introduced at home and abroad at present; Electrochemical hydrogen pumps constructed by CaZr0.9In0.1O3-α, BaCe0.90Y0.10O3-α, BaCe0.85Y0.15O3-αand BaCe0.90Sm0.10O3-αas electrolytes were used to dehydrogenate molten aluminium and the hydrogen content was detected by the sensors constructed by CaZr09In0.1O3-αas electrolyte by electrochemical method (6th Chapter); At the end of the paper, the discussions were summed up (7th Chapter) and further studying on perovskite-type proton conductors and its development direction was described (8th Chapter). The main research results of this work were reported as follows:(1) The powder particles were refined by prolonging the milling time of original mixture properly, which can not only lower the synthesis temperature of BaCe0.90Y0.10O3-αor Ba3Ca1.18Nb1.82O9-δ, but also can synthesize the powders with small particle size, narrow particle size distribution and large specific surface area. As a result, the densities and electrical properties of sintered samples were improved, respectively.(2) The conductivities of BaCe0.90Sm0.10O3-α,BaCe0.90Y0.10O3-αand BaCe0.85Y0.15O3-αproton conductors increased, whose activation energies decreased in turn at 573-873K in air. This result indicates that the electrical properties of BaCeO3-based materials also can be improved by means of increasing the concent of Y3+ion or doping the ion whose radius is close to the radius of Ce4+ion.(3) A set of reasonable parameters for forming CaZr0.9In0.1O3-αtubes by hot pressure casting included the casting pressure 0.5MPa, the duration of pressure 15s, the mold temperature 30℃, the wax material temperature 73℃, the wax material composed of powders 87.8%, paraffin 11%, beeswax 1%, oleic acid 0.2% and the wax removal temperature 1000℃. The content of In3+ion decreased in the sintered samples, which was due to the dissociation of In2O3 for InO and O2 during the sintering.(4) Electrochemical hydrogen pump constructed by CaZr0.9In0.1O3-αas electrolyte was used to dehydrogenate the molten Aluminium by vacuum extracting, gas carrying or applied voltage method, respectively. The results showed that the fastest dehydrogenating rate was realized by applying voltage 1.5V, and then vacuum extracting. The dehydrogenating rate by gas carrying was relatively low. The effect of oxygen gas carrying was better than that of argon gas carrying.(5) The molten Aluminium is dehydrogenated by an electrochemical hydrogen pump constructed by BaCe0.90Sm0.10O3-α, BaCe0.85Y0.15O3-αand BaCe0.90Y0.10O3-αas electrolyte in molten aluminium at 760℃,780℃and 800℃, at water vapor pressure between 4122.8Pa and 4754.7Pa and applied voltage of 0.4V,0.8V and 1.2V, respectively. The results exhibited that the current in the pumps became larger when the temperature in molten Aluminium, water vapor pressure or applied voltage increased.(6) The mixture of YH0.55+YH0.9 was synthesized as a new type of reference electrode material. The response time of the hydrogen sensor constucted by CaZr0.9In0.1O3-αas electrolyte and YH0.55+YH0.9 as reference electrode was about 20s.更多还原