The novel sulfonated polybenzimidazole(sPBI)/amine functionalized titanium dioxide(AFT) composite membrane is devised and studied for its capability of the application of high temperature proton exchange membrane fuel...The novel sulfonated polybenzimidazole(sPBI)/amine functionalized titanium dioxide(AFT) composite membrane is devised and studied for its capability of the application of high temperature proton exchange membrane fuel cells(HT-PEMFCs),unlike the prior low temperature AFT endeavors.The high temperature compatibility was actualized because of the filling of free volumes in the rigid aromatic matrix of the composite with AFT nanoparticles which inhibited segmental motions of the chains and improved its thermal stability.Besides,amine functionalization of TiO2 enhanced their dispersion character in the sPBI matrix and shortened the interparticle separation gap which finally improved the proton transfer after establishing interconnected pathways and breeding more phosphoric acid(PA) doping.In addition,the appeared assembled clusters of AFT flourished a superior mechanical stability.Thus,the optimized sPBI/AFT(10 wt%) showed 65.3 MPa tensile strength;0.084 S·cm^-1 proton conductivity(at 160℃;in anhydrous conditions),28.6% water uptake and PA doping level of 23 mol per sPBI repeat unit.The maximum power density peak for sPBI/AFT-10 met the figure of0.42 W·cm^-2 at 160℃(in dry conditions) under atmospheric pressure with 1.5 and 2.5 stoichiometric flow rates of H2/air.These results affirmed the probable fitting of sPBI/AFT composite for HT-PEMFC applications.展开更多
硫铁矿烧渣是硫铁矿生产硫酸过程中产生的固体废弃物,其大量堆积带来了严重的生态环境问题。经适当处理的硫铁矿烧渣中较高价的铁含量高,若能提取利用,不仅可以解决生态环境问题,还可以带来一定的经济效益。本文通过添加固体还原剂高温...硫铁矿烧渣是硫铁矿生产硫酸过程中产生的固体废弃物,其大量堆积带来了严重的生态环境问题。经适当处理的硫铁矿烧渣中较高价的铁含量高,若能提取利用,不仅可以解决生态环境问题,还可以带来一定的经济效益。本文通过添加固体还原剂高温焙烧,成功将硫铁矿烧渣中较高价的铁(Fe 2 O 3)还原为较低价的铁(Fe 3 O 4)。通过单因素试验,得到了较优的还原焙烧条件:在850~900℃下焙烧45~60 min,还原剂化学计量比为1.4~1.7;较优的酸浸条件:硫酸质量分数为30%~40%,硫酸化学计量比为1.2~1.4,浸取时间在30 min以上。在上述条件下,铁的浸出率高达98%。对酸浸液进行除杂处理,利用除杂后的硫酸亚铁净化液制备了磷酸铁产品,经检测,产品质量达到了HG/T 4701-2021《电池用磷酸铁》的技术指标要求。研究成果为硫铁矿烧渣的高值利用提供了一条新途径。展开更多
基金supported by the National Natural Science Foundation of China(Nos.21776034,21476044 and 21406031)Joint Funds of the National Natural Science Foundation of China(U1663223)+1 种基金National Key Research and Development Program of China(2016YFB0101203)Changjiang Scholars Program(T2012049)。
文摘The novel sulfonated polybenzimidazole(sPBI)/amine functionalized titanium dioxide(AFT) composite membrane is devised and studied for its capability of the application of high temperature proton exchange membrane fuel cells(HT-PEMFCs),unlike the prior low temperature AFT endeavors.The high temperature compatibility was actualized because of the filling of free volumes in the rigid aromatic matrix of the composite with AFT nanoparticles which inhibited segmental motions of the chains and improved its thermal stability.Besides,amine functionalization of TiO2 enhanced their dispersion character in the sPBI matrix and shortened the interparticle separation gap which finally improved the proton transfer after establishing interconnected pathways and breeding more phosphoric acid(PA) doping.In addition,the appeared assembled clusters of AFT flourished a superior mechanical stability.Thus,the optimized sPBI/AFT(10 wt%) showed 65.3 MPa tensile strength;0.084 S·cm^-1 proton conductivity(at 160℃;in anhydrous conditions),28.6% water uptake and PA doping level of 23 mol per sPBI repeat unit.The maximum power density peak for sPBI/AFT-10 met the figure of0.42 W·cm^-2 at 160℃(in dry conditions) under atmospheric pressure with 1.5 and 2.5 stoichiometric flow rates of H2/air.These results affirmed the probable fitting of sPBI/AFT composite for HT-PEMFC applications.
文摘硫铁矿烧渣是硫铁矿生产硫酸过程中产生的固体废弃物,其大量堆积带来了严重的生态环境问题。经适当处理的硫铁矿烧渣中较高价的铁含量高,若能提取利用,不仅可以解决生态环境问题,还可以带来一定的经济效益。本文通过添加固体还原剂高温焙烧,成功将硫铁矿烧渣中较高价的铁(Fe 2 O 3)还原为较低价的铁(Fe 3 O 4)。通过单因素试验,得到了较优的还原焙烧条件:在850~900℃下焙烧45~60 min,还原剂化学计量比为1.4~1.7;较优的酸浸条件:硫酸质量分数为30%~40%,硫酸化学计量比为1.2~1.4,浸取时间在30 min以上。在上述条件下,铁的浸出率高达98%。对酸浸液进行除杂处理,利用除杂后的硫酸亚铁净化液制备了磷酸铁产品,经检测,产品质量达到了HG/T 4701-2021《电池用磷酸铁》的技术指标要求。研究成果为硫铁矿烧渣的高值利用提供了一条新途径。