K0.1Sr0.9Co0.8Fe0.2O3-δ透氧膜材料的合成及透氧性能研究  

Synthesis of K0.1Sr0.9Co0.8Fe0.2O3-δoxygen permeable materials and their oxygen permeability

作　　者：刘力魁 刘威 李佳 杨微 李芳[1] 李其明[1] LIU Likui;LIU Wei;LI Jia;YANG Wei;LI Fang;LI Qiming(School of Chemistry, Chemical Engineering and Environmental Engineering,Key Laboratory of Petrochemical Industry of Liaoning Province, Liaoning Shihua University,Fushun 113001, China)

机构地区：[1]辽宁石油化工大学,化学化工与环境学部,辽宁省教育厅石油化工重点实验室,抚顺113001

出　　处：《膜科学与技术》2020年第2期45-52,共8页Membrane Science and Technology

基　　金：国家自然科学基金项目(21703091,21201096);辽宁省教育厅资助项目(L2019009);辽宁省科技厅计划指导项目(2019-ZD-0058)。

摘　　要：通过溶胶凝胶法制备了一种新型钾离子掺杂钙钛矿透氧膜材料K0.1Sr0.9Co0.8Fe0.2O3-δ(KSCF),并系统考察了该透氧膜材料的透氧量、稳定性和速率控制步骤等.XRD表征显示,钾离子在钙钛矿A位掺杂量低于或等于10%不会改变KSCF立方钙钛矿结构.SEM分析显示,KSCF膜片在1220℃焙烧可高度致密,并且KSCF长期放置仍然保持了高机械强度,不会出现类似SrCo0.8Fe0.2O3-δ(SCF)材料的粉化解体.氧渗透实验结果表明,操作温度的升高、膜片厚度的降低以及吹扫气流速的增加均有利于膜片透氧量的提升,厚度为0.5 mm的KSCF膜片在950℃时的透氧量可达2.65 mL/(cm^2·min).对比实验表明,基于同样测试条件KSCF透氧膜的透氧量比SCF材料的透氧量更高.通过对KSCF膜片的速率控制步骤考察可以发现,当KSCF透氧膜膜片厚度低于0.7 mm时,其透氧过程为表面交换控制,当膜片厚度高于0.7 mm时,其透氧过程则会转化为体相扩散控制.A potassium-doped K0.1Sr0.9Co0.8Fe0.2O3-δ(KSCF)perovskite material was successfully prepared by a sol-gel method.Oxygen permeability,structural stability and rate-determined step were investigated systematically.XRD characterization shows that while the potassium doping content is lower than or equal to 10%,KSCF cubic perovskite phase can be obtained.SEM results show that the highly dense KSCF membrane disk can be attained at 1220℃.Moreover,KSCF membrane disk possesses excellent mechanical strength under the long-term air condition,which cannot be disintegrated spontaneously as SrCo0.8Fe0.2O3-δmaterial(SCF).Oxygen permeation test shows that the increase of operation temperature,the decrease of membrane thickness and the increase of purge gas flow rate are beneficial to improve oxygen permeation flux of KSCF membranes.Especially,it can be found that oxygen flux of KSCF membrane with a thickness of 0.5 mm can reach about 2.65 mL/(cm^2·min)at 950℃.Further comparison experiment indicates that oxygen permeability of KSCF membrane is also higher than SCF under the same measurement conditions.Through investigating the rate-determining steps of KSCF membranes,it can be found that while the KSCF membrane thickness is lower than 0.7 mm,oxygen permeation of KSCF membranes is determined by surface exchange process.While KSCF membrane thickness is higher than 0.7 mm,their oxygen permeation is determined by bulk diffusion process.

关 键 词：透氧膜 钙钛矿 钾离子 透氧量 稳定性 

分 类 号：TQ028.8[化学工程]