中文摘要：

为增加电极的活性面积，采用两步电沉积制备具有高活性面积的铅电极．先以铜棒为基质恒电位氢气泡模板法沉积多孔铜层，再以多孔铜层为基质电沉积铅．x射线衍射（XRD）结果表明铅为立方结构，扫描电镜（SEM）显示四方柱状铅粒均匀沉积在多孔铜层的孔壁上，呈现三维多孔形貌．电沉积铅电极用于CO2电还原反应，循环伏安（CV）测试结果表明，其比普通铅片电极具有更正的起峰电位和更高的电流密度．在施加电位为-1．7V（相对饱和甘汞电极）、KHCO3电解液浓度为0．3mol／L时，生成甲酸的最高电流效率达到92％．对CO2电还原过程影响因素的研究表明：在低电流密度区，随电流密度的增加，生成甲酸的电流效率和速率都增加；在高电流密度区，随电流密度增加，生成甲酸的速率增加，而生成甲酸电流效率逐渐降低．时长为1h的CO2电还原反应中，产物甲酸的电流效率逐渐降低，对比反应前后电沉积铅电极的XRD谱图和SEM图发现，铅仍为立方结构，而形貌发生显著变化，铅由四方柱状变为层状覆盖在多孔铜层颗粒的表面．电极的活性面积减小是甲酸电流效率降低的主要原因．

英文摘要：

Absract： To enhance the active area of electrode, modified Pb electrode with high active area was prepared by two steps of electrodepositon. Firstly, a porous copper film was deposited onto a copper stick by means of hydrogen bubble dynamic template at constant potential. Then Pb was deposited onto the porous copper film, which was a hard template, by constant potential electrodeposition. Morphology and structure of the self-made electrodeposited Pb electrode were characterized by scanning electron microscopy （SEM）and X-ray diffraction （XRD）respectively. XRD results show that the structure of Pb is cubic and SEM results show the morphology of lead is cuboid and Pb is uniformly deposited on the porous copper film, showing a three-dimensional porous morphology. This self-made Pb electrode was used in the process of CO2 electroreduction. Cyclic voltammetry （CV） tests reveal more positive onset potential and larger current density of the self-made Pb electrode than the ordinary plated Pb electrode. The highest current efficiency of the process reaches 92% when applied potential is - 1.7 V vs. SCE （saturated calomel electrode） and KHCO3 electrolyte is 0.3 mol/L. Experimental results of the CO2 reduction process in different applied potentials and different concentrations of KHCO3 electrolytes reveal that, in low current density region, current efficiency of formic acid and production rate of formic acid increase with the increase of current density; and in the high current density region, formic acid production rate increases, while current efficiency of formic acid decreases with the increase of current density. In the one hour electroreduction process, current efficiency decreases with time extension. Comparing XRD and SEM of electrodes before and after reaction, it is indicated Pb has kept its cubic form, but its morphology have obviously changed from cuboid to stratiform covering on the surface of porous Cu particles. Therefore, the decrease in electroactive surface might be the main reason leadi