La/Ni共掺杂SrTi_(0.35)Fe_(0.65)O_(3-δ)对称电极用于SOEC共电解H_(2)O/CO_(2)研究

Study on La/Ni co-doped SrTi_(0.35)Fe_(0.65)O_(3-δ)symmetric electrode for H_(2)O/CO_(2) co-electrolysis in SOECs

通过固体氧化物电解池(SOEC)电解水蒸气制氢及共电解H_(2)O/CO_(2)生产合成气是拓展可再生能源应用、促进化学工业绿色低碳转型的重要技术路线。面向SOEC对高性能、稳定电极的需求,采用La/Ni共掺杂SrTi_(0.35)Fe_(0.65)O_(3-δ)的电极策略,设计并制备了La_(0.1)Sr_(0.8)5Ti_(0.35)Fe_(0.6)Ni_(0.05O_(3)(LSTFN),并将其同时作为SOEC的氢电极和氧电极。通过扫描电子显微镜(SEM)、能量分散光谱(EDS)和X射线衍射(XRD)等方法,对LSTFN电极结构组成及微观形貌演化进行研究,并考察了单电池共电解H_(2)O/CO_(2)性能和可逆运行稳定性。结果表明,在还原气氛中,LSTFN氢电极表面原位析出了纳米Ni-Fe合金颗粒,并在含水和含碳复杂气氛中稳定存在;在800℃,10%H_(2)保护气和1.8 V的条件下(H_(2)/H_(2)O/CO_(2)=10∶45∶45),LSTFN的共电解电流达到了1.8 A/cm^(2),并在发电/电解可逆条件下稳定运行,表现出良好的应用前景。

Hydrogen production from water steam electrolysis powered by solid oxide electrolysis cells(SOECs)and syngas production by co-electrolysis of H_(2)O/CO_(2) are important routes to promote the application of renewable energy and development of green and low-carbon chemical industry.To meet the demands for high performance and stable operation of SOECs,La/Ni co-doped SrTi_(0.35)Fe_(0.65)O_(3-δ)strategy was adopted,and La_(0.1)Sr_(0.8)5Ti_(0.35)Fe_(0.6)Ni_(0.05O_(3)(LSTFN)was designed and prepared as both hydrogen and oxygen electrodes for SOECs.The structural composition and micromorphological evolution of LSTFN electrode were investigated by scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS)and X-ray diffraction(XRD).The H_(2)O/CO_(2) co-electrolysis performance and reversible operation stability were examined.The results show that,Ni-Fe alloy nanoparticles in-situ precipitated on LSTFN hydrogen electrode surface are stable in complex steam and carbon-containing atmospheres.The LSTFN co-electrolysis current reaches 1.8 A/cm^(2) in 800℃,1.8 V and 10%H_(2) protective atmosphere(H_(2)/H_(2)O/CO_(2)=10∶45∶45).LSTFN symmetric cell performs stably in reversible operations between power generation and co-electrolysis,showing good application prospects.