中文摘要：

采用共沉淀法制备SnO_2-CuO复合纳米催化剂,用于温室气体CO_2电催化还原。实验结果表明：催化活性的强弱取决于复合催化剂中的SnO_2和CuO的摩尔比。催化剂SnO_2（50%）-CuO（50%）的催化条件为最优,起峰电位可达到-0.75V,而在-1.25V时的最大电流密度能达到约-24 mA/cm~2。测试结果表明,SnO_2（50%）-CuO（50%）/GDL的电容为200μF/cm~2,比无负载的气体扩散电极（GDL）面积增加了30μF/cm~2。复合催化剂平均粒径约为50nm,颗粒间隙为100nm,其疏松的结构对CO_2与催化剂的接触非常有利。离子色谱与电流-时间的关系表明SnO_2（50%）-CuO（50%）在-1.0V（vs SHE）电位下电解1h,可得到最优法拉第效率,高达74.1%。SnO_2（50%）-CuO（50%）复合催化剂的稳定性可高达30h。复合SnO_2-CuO纳米催化剂具有优良的CO_2电化学还原催化性能。

英文摘要：

Composite SnO2-CuO nanocatalysts were prepared by co-precipitation methods, and applied to the technique about greenhouse gases CO2 electroreduction. The result indicates that catalytic activity of composite SnO2-CuO depended on the molar ratio of SnO2 and CuO. When the ratio of SnO2 was 50%, the SnO2 （50%）- CuO（50%） showed the best catalytic performance. The onset potential of SnO2 （50%）-CuO（50%） could reach to --0.75 V and the current density at --1.25 V could be as high as about --24 mA/cm^2. Test results show that the electric capacity of SnO2 （50%）-CuO（50%）/GDL was as high as 200 μF/cm^2 and had more 30μF/cm^2 than the area of gas diffusion electrode （GDL）. SnO2 （50%）-CUO（50%） was made up of nanoparticles with an aver- age diameter of about 50 nm. The length between particles was about 100 nm, which was good for the contact between CO2 and electroreduction. Ion chromatography measurement demonstrates that when electrolysis at --1.0 V for 1 h, the maximum Faraday efficiency of formic acid could be high up to 74.1%. The stability of SnO2 （50%）-CUO（50%） was outstanding after even 30 hours electrolysis. So the SnO2-CuO nanocatalysts have great catalytic activity.