摘要
熔盐电解技术可以将温室气体CO2直接转化为可再次利用的高附加值固体碳材料,故而被认为是解决全球气候变化的可行途径。以熔融态Li2CO3为电解质,铂为对电极,通过极化曲线测试研究了铁、镍、铜以及316不锈钢等金属材质在熔盐电解过程中的极化行为;通过循环伏安测试考察了不同电极组合中阴极表面的电极过程,旨在深入理解熔盐电解还原生碳机理;采用场发射扫描电镜、X射线衍射分析仪、拉曼光谱仪对阴极碳材料的微观形貌、结晶度、石墨化程度等物化特性进行了表征分析。研究结果表明:铁作阴极、镍作阳极在熔盐电解池中的极化作用最小,即驱动还原生碳过程所需的过电势最低;CV测试中,-1.0~-1.5 V区间内阴极表面均可明显观察到明显的CO32-还原峰;铁作阴极、镍或铜作阳极时,阴极产物中含有大量碳纳米管,直径约为100nm。本文揭示了铁、镍、铜及316不锈钢等4种常规金属材质分别作为阴阳极时对熔融Li2CO3电解过程的影响,明确了合成碳纳米管的最优电极组合,为后续规模化研究奠定了理论基础。
Molten salt electrochemistry provides a direct and facile pathway to convert CO2 into reusable high value-added solid carbon materials,which is therefore recognized as an effective candidate to address the thorny problem of global climate change.Polarization behavior of Fe,Ni,Cu and 316 steel was analyzed by polarization measurements.Cyclic voltammetry(CV)was performed in order to gain a more in-depth understanding on the carbon deposition at the cathode surface.Scanning electron microscope(SEM),X-ray diffractometer and Raman spectrometer were employed to characterize the morphology,crystallinity and graphitization of the cahodically formed carbon materials.The results demonstrated that Fe as cathode and Ni as anode were superior to other electrode combinations,the required energy to drive the carbon production was the lowest.During the CV measurements,reduction peak could be obviously observed within the potential range of-1.0~-1.5 V.When Fe was used as cathode,Ni or Cu was used as anode,large amounts of CNTs were observed in the carbon products with a diameter of approximate 100 nm.This work discloses the electrochemical behavior of Fe,Ni,Cu and 316 steel during the molten Li2CO3 electrolysis,and confirms that Fe and Ni are the optimum candidate of cathode and anode respectively,which should be of great interest for following industrialization.
作者
张文勇
ZHANG Wen-yong(College of Chemistry and Chemical Engineering,Northeast Petroleum University,Daqing 163318,China)
出处
《当代化工》
CAS
2020年第11期2477-2481,共5页
Contemporary Chemical Industry
关键词
碳酸锂
二氧化碳
极化测试
循环伏安
碳纳米管
Li2CO3
Carbon dioxide
Polarization measurements
Cyclic voltammetry
Carbon nanotubes
