摘要
研究了Sn气体扩散电极(SGDE)上电化学还原CO_2制甲酸(ERCF)性能的稳定性。采用X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线能量色散谱(EDX)和活性表面积测试等技术手段分别表征SGDE在电化学还原CO_2制甲酸过程前后的物相结构、表面形貌、元素组成和活性表面积。采用生成甲酸的法拉第效率(fHCOOH)评价SGDE上电化学还原CO_2制甲酸的性能。结果显示,fHCOOH随电解时间的延长急剧地降低,电解时间12 h的fHCOOH((36.6±1.6)%)比电解时间0.5 h时的fHCOOH((78.5±0.1)%)降低了53%。SGDE在12 h电还原反应后,表面沉积了微量Fe,而且Sn含量(质量分数)减少了66%,活性表面积降低了41%。进一步的研究发现,沉积的微量Fe对电化学还原CO_2制甲酸过程基本没有影响,Sn含量和活性表面积的降低可能是SGDE上电化学还原CO_2制甲酸性能降低的主要原因。
The stability of Sn gas diffusion electrode (SGDE) for electrochemical reduction of CO2 to formic acid(ERCF) was investigated. The crystal structure, morphology, chemical composition and active surface area of the SGDE were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy and active surface area measurement, respectively. The Faraday efficiency of formic acid (fHcooH) was measured in order to evaluate the catalytic performance of ERCF over the SGDE. The results show that fHCOOH decreases sharply with the electrolysis time. The fHcooH at the electrolysis time of 12 h ( (36.6 ± 1.6) % ) is 53% lower than that at 0. 5 h( (78.5±0. 1 ) % ). After the electrolysis of 12 h, trace Fe is deposited on the surface of the SGDE. In addition, the Sn content (mass fraction) and active surface area of the SGDE are reduced by 66% and of trace Fe has no effect on ECRF and the d content and active surface area 41%, respectively. Further examinations show that the deposition egradation of the SGDE can be attributed to the reduction in the Sn
出处
《应用化学》
CAS
CSCD
北大核心
2016年第10期1189-1195,共7页
Chinese Journal of Applied Chemistry
基金
国家自然科学基金(41171418)
国家大学生创新训练项目(201510357031)
安徽大学博士科研启动资金项目(J01001965)资助~~
关键词
电化学还原
二氧化碳
甲酸
锡气体扩散电极
稳定性
electrochemical reduction
carbon dioxide
tin gas diffusion electrode
formic acid
stability