核壳结构Ni@Au/C用作DBFC阳极催化剂

Studies of anode catalyst of sodium borohydride fuel cell

采用连续两步化学还原法制备了Ni-Au摩尔比为1∶1的碳载核壳结构(Ni@Au/C)纳米粒子。通过X射线衍射(XRD)和透射电镜(TEM)对其结构进行表征,以循环伏安(CV)、计时电位(CP)、计时电流(CA)和电池测试技术对BH4-电化学氧化活性进行测试。结果表明,所制备的核壳结构纳米粒子直径在10nm左右,其电化学活性面积为815.7cm2/mg,约是实心纳米Au/C催化剂的5倍,且对BH4-电氧化反应显示出更好的催化活性。以Ni@Au/C为阳极催化剂,Pt网(1cm×1cm)为阴极组装的单电池在20℃时最大功率密度达到74mW/cm2。

Carbon supported core-shell structure Ni-Au （Ni@Au/C） nanoparticles with the proportion of 1：1 was prepared by a two-step reduction method. The structure of the as-prepared catalysts was investigated by transmission electron microscopy （TEM） and X-ray diffraction （XRD）, and the electro-oxidation activity towars to BH4-were tested by cyclic voltammetry （CV）, chronopotentiometry （CP）, chrenoamperemetry （CA） and fuel cell test. The results show as follows： the size of the core-shell structure nanoparticlas is approximately 10 nm, and the electrochemically active surface area （ECSA）, 815.7 cm2/mg, is obtained, which is four times higher than that of Au/C catalyst. And a higher catalytic activity towards the electro-oxidation of BH4-was exhibited of the Ni@Au/C catalyst. A single cell, which was fabricated using Ni@Au/C as anode catalysts and Pt mesh （1 cm × 1 cm） as cathode electrode, achieved a maximum power density of 74 mW/cm2 at 20 ℃.