Enhanced CO2 Electrolysis with Metal-oxide Interface Structures

The ever-decreasing fossil fuels and the increasing greenhouse effect have caused substantial concern.Solid oxide electrolyser cell(SOEC)with La_0.75Sr_0.25Cr_(0.5 )Mn_0.5O_3-δ(LSCM)as a cathode was used for CO₂ electrolysis to CO.In this work,the metal-oxide interface was constructed on the LSCM framework by in-situ exsolution and impregnation,and the uniform distribution of metal nanoparticles on the LSCM framework was confirmed by spectroscopy techniques and electron microscopy techniques.The existence of three-phase boundary promoted the absorption and electrolysis of CO₂.(La_0.75 Sr_0.25)0.9(Cr_(0.5 )Mn_0.5)_0.9(Ni_0.5 Cu_0.5)_0.1 O_3-δ(LSCMNC)showed the best electrolytic CO₂ performance at 850℃and exhibited excellent electrocatalytic activity after 100 hours of long-term testing and 8 redox cycles.     

Perovskite Sr_(0.9)Fe_(0.9)Zr_(0.1)O_(3-δ):Redox-stable Structure,Oxygen Vacancy,Electrical Properties and Steam Electrolysis Performance

Many researchers have studied on perovskite oxide for its unique structure.Perovskite oxides,ABO_(3-δ),with different A and B metals have shown wide applications in many fields,in particular solid oxide electrolysers.SrFeO_(3-δ),typical perovskite oxides,in which iron is the mixed-valence cation with the capacity to change the chemical valence,have a wide range of oxygen nonstoichiometry.In this study,Sr_(0.9)Fe_(0.9)Zr_(0.1)O_(3-δ)(SFZO) is synthesized and then treated in 5%H_2/Ar and air at high temperature,exhibiting excellent redox stability.Redox-stable structure,oxygen vacancy and electrical properties of SFZO are investigated.Steam electrolysis is then performed with SFZO cathode under 5%H_2O/5%H_2/Ar and 5%H_2O/Ar atmospheres,respectively.The present results indicate that the SFZO is a novel promising cathode material for solid oxide steam electrolyser.     

氧离子传导型固体氧化物电解池燃料电极的研究进展

固体氧化物电解池可高效地电解H₂O/CO₂制备燃料,越来越受到人们的重视. 本文对近年来在燃料电极（阴极）材料方面的研究进展进行了全面综述,指出各种阴极材料的优缺点及发展趋势,强调亟待解决的关键科学与技术问题.     

氧化还原可逆Nb2TiO7复合阴极电解池高温水蒸气电解研究

系统地研究Nb₂TiO₇与Nb_1.33Ti_0.67O₄材料相互转变的氧化还原循环可逆性能,同时研究Nb2TiO7和Nb_1.33Ti_0.67O₄样品随温度和氧分压变化的电导率,并与复合电极对称电池和电解池的电化学性能相关联. 在830 oC下,对Nb_1.33Ti_0.67O₄复合电极电解池进行水蒸气的电解研究测试. 电流电压曲线和电解池短期性能测试表明在低电压下主要为电极的还原和活化过程;而在高电压下主要为水蒸气的电解. 当3%H₂O/Ar/4%H_{2气体通入阴极时电解池水蒸气电解的法拉第效率为98.9%;而当通入气体转换为3%H2O/Ar时效率为89%.}     

锰掺杂的钙钛矿型钛铌酸盐基复合阴极高温电解水蒸气

通过在氧化还原稳定的钙钛矿材料钛铌酸盐的B位晶格中掺杂具有氧化还原活性的锰元素提高固体氧化物电解池复合电极电催化性能．研究发现,锰元素成功取代钛铌酸盐B位的Ti／Nb．掺杂后的样品的离子电导率在800℃下的氧化气氛和还原气氛下的离子电导率分别提高了约1和0．5个数量级．基于掺杂后的钛铌酸盐基复合阴极,氧离子传导型固体氧化物电解池电解水蒸汽的电流效率在有和无还原气体保护下分别提高了25％和30％．     

锰掺杂的钙钛矿型钛铌酸盐基复合阴极高温电解水蒸气

通过在氧化还原稳定的钙钛矿材料钛铌酸盐的B位晶格中掺杂具有氧化还原活性的锰元素提高固体氧化物电解池复合电极电催化性能．研究发现,锰元素成功取代钛铌酸盐B位的Ti/Nb．掺杂后的样 品的离子电导率在800 oC下的氧化气氛和还原气氛下的离子电导率分别提高了约1和0.5个数量级．基于掺杂后的钛铌酸盐基复合阴极,氧离子传导型固体氧化物电解池电解水蒸汽的电流效率在有和无还原气体保护下分别提高了25%和30%．     

钙钛矿型中温固体氧化物燃料电池阴极Ba0.5Sr0.5Al0.1Fe0.9O3-δ

研究一种新型不含钴的钙钛矿型中温固体氧化物燃料电池阴极Ba_0.5Sr_0.5Al_0.1Fe_0.9O_3-δ (BSAF)材料的晶体结构、电导率以及在对称电池中的电极极化性能. 研究发现,BSAF阴极在空气中低于450 oC表现出典型的具有正温度系数的半导体行为,最高电导率达到14 S/cm;在450-750 oC,却表现出负温度系数,且电导率在750 oC下降到6 S/cm. 电化学研究表明,在基于混合离子导体的对称电池中,BSAF阴极在650-700 oC表现出良好的电极极化性能.以3%H₂O/H₂为燃料和空气为氧化剂,单电池在700 oC的开路电压和最大功率输出分别达到420 mW/cm².     

基于可逆固体氧化物电池堆的电能高效存储

研究了固体氧化物电池堆中电能的可逆存储与产生,通过相变金属存储燃料电池模式下的热能并在电解池模式下加以利用. 系统的荷电状态(即氢燃料百分比)可显著增加开路电压,系统压力的增加有效提高了开路电压. 较高的系统压力可促进电极表面的物质扩散和输运,相应地改善电极的极化电阻. 通过有效的热能管理,系统的电能可逆存储的循环效率可高达92%.     

Porous Iron-and Cobalt-based Single Crystals with Enhanced Electrocatalysis Performance

Porous single crystals have the characteristics of long-range ordering structure and large specific surface area,which will significantly enhance their electrochemical performance.Here,we report a method different from the conventional porous single crystal growth method.This method is to directly convert single crystal precursors Co₃O₄ and Fe₃O₄ into Co₂N and Fe₂N,and then further reduces them to porous single crystals Co and Fe particles under H2/Ar atmosphere.The removal of O^2–in the lattice channel at the pressure of 25~300 torr and the temperature of 300~600℃ will promote nitridation of the single-crystalline Co–O and Fe–O frames,and further remove N^3–in H2/Ar atmosphere and recrystallize as Co and Fe.These porous single crystals exhibit enhanced electrochemical properties due to their structural coherence and highly active surface.We demonstrated that the aminobenzene yield was up to 91%and the selectivity reached 92%in the electrochemical reduction of nitrobenzene.