Although intermediate temperature solid oxide fuel cells(IT-SOFCs)show great potential to address energy conversion challenges,the sluggish oxygen reduction reaction(ORR)kinetics of cathode materials has severely hind...Although intermediate temperature solid oxide fuel cells(IT-SOFCs)show great potential to address energy conversion challenges,the sluggish oxygen reduction reaction(ORR)kinetics of cathode materials has severely hindered extended applications.Herein,we have demonstrated that Bi^(3+)doping on the A-site synergistically regulates the phase transition and electron spin state in La_(0.3)Bi_(0.3)Ca_(0.4)FeO_(3-δ)(LBCF3)for improved performance.An orthorhombic to cubic phase transition occurred with Bi^(3+)doping increases oxygen vacancy concentration and thus increases oxygen ion migration capacity.Simultaneously,the change of Fe from low to medium electron spin state strengths O_(2)adsorption and improves catalytic performances.Consequently,a peak power density improvement up to 48%(from 1.21 to 1.79 W·cm^(-2))at 800℃ is realized in the anodesupported single cell using LBCF3 as cathode,which remains stable for over 270 h at 750℃.展开更多
喷雾热解法是制备纳米CeO_(2)粉体的途径之一,但液滴在高速高温气流中发生的蒸发、破碎和热解行为影响了最终产品的性能和品质。本文基于VOF(Volume of fluid)蒸发传质模型与有限速率化学反应模型的耦合方法,研究了热解中液滴形貌以及...喷雾热解法是制备纳米CeO_(2)粉体的途径之一,但液滴在高速高温气流中发生的蒸发、破碎和热解行为影响了最终产品的性能和品质。本文基于VOF(Volume of fluid)蒸发传质模型与有限速率化学反应模型的耦合方法,研究了热解中液滴形貌以及流场的变化和产物分布随时间的全过程。结果表明:当入口气流速度为60 m/s、温度为650℃时,液滴在破碎前的形貌发生了变化,即液滴表面先出现波纹状起伏,然后加剧为褶皱状起伏,最后转变为沟壑状起伏;液滴迎风面与背风面存在压力差,流场中局部(液滴边缘)气流速度最大为67 m/s;子液滴数量沿X轴正方向不断减少且周围有产物CeO_(2)生成,计算域内产物CeO_(2)含量随时间的延长而逐渐增大;产物CeO_(2)主要生成于气相与氧化剂的交界面处,而非直接附着在液滴表面。展开更多
基金supported by the Xinjiang Autonomous Region Key Research Project(No.2022D01D31)the Start-up Grant of Xinjiang University,the Basic Research Fund for Autonomous Region Universities(No.XJEDU2024P015)the Natural Science Foundation of Xinjiang Uygur Autonomous Region(No.2022D01C668).
文摘Although intermediate temperature solid oxide fuel cells(IT-SOFCs)show great potential to address energy conversion challenges,the sluggish oxygen reduction reaction(ORR)kinetics of cathode materials has severely hindered extended applications.Herein,we have demonstrated that Bi^(3+)doping on the A-site synergistically regulates the phase transition and electron spin state in La_(0.3)Bi_(0.3)Ca_(0.4)FeO_(3-δ)(LBCF3)for improved performance.An orthorhombic to cubic phase transition occurred with Bi^(3+)doping increases oxygen vacancy concentration and thus increases oxygen ion migration capacity.Simultaneously,the change of Fe from low to medium electron spin state strengths O_(2)adsorption and improves catalytic performances.Consequently,a peak power density improvement up to 48%(from 1.21 to 1.79 W·cm^(-2))at 800℃ is realized in the anodesupported single cell using LBCF3 as cathode,which remains stable for over 270 h at 750℃.
文摘喷雾热解法是制备纳米CeO_(2)粉体的途径之一,但液滴在高速高温气流中发生的蒸发、破碎和热解行为影响了最终产品的性能和品质。本文基于VOF(Volume of fluid)蒸发传质模型与有限速率化学反应模型的耦合方法,研究了热解中液滴形貌以及流场的变化和产物分布随时间的全过程。结果表明:当入口气流速度为60 m/s、温度为650℃时,液滴在破碎前的形貌发生了变化,即液滴表面先出现波纹状起伏,然后加剧为褶皱状起伏,最后转变为沟壑状起伏;液滴迎风面与背风面存在压力差,流场中局部(液滴边缘)气流速度最大为67 m/s;子液滴数量沿X轴正方向不断减少且周围有产物CeO_(2)生成,计算域内产物CeO_(2)含量随时间的延长而逐渐增大;产物CeO_(2)主要生成于气相与氧化剂的交界面处,而非直接附着在液滴表面。
