电沉积法制备钴硒化合物及其氧还原性能研究

发布时间：2018-04-25 22:19

  本文选题：燃料电池 + 氧还原催化剂　； 参考：《哈尔滨工业大学》2017年硕士论文

【摘要】：燃料电池是一种通过电化学反应,直接将储存在燃料中的化学能转换为电能的绿色发电装置。而人们一直在寻找可以替代Pt的非贵金属燃料电池阴极催化剂,以解决成本高的问题。Co-Se化合物对氧还原反应具有较强的催化能力。电沉积法合成Co-Se化合物可以将催化剂直接电沉积到膜电极的活性位点上,能够极大地提高催化剂的利用率。而且关于电沉积法用于燃料电池氧还原催化剂的研究比较少,所以本文对电沉积Co-Se化合物氧还原催化剂进行了研究。首先采用恒电势电沉积法在铜片上电沉积Se薄膜,在以主盐为SeO2的水溶液中研究了电沉积Se的电化学行为,结果表明Se的沉积过程分三步进行,先发生Se的四电子还原,再发生Se的六电子还原,最后在电极表面发生化学还原。探究了沉积电位、主盐浓度、温度、pH对电沉积Se薄膜形貌和结构的影响,分别在20 ℃和40 ℃时得到了具有单斜晶系结构和六方晶系结构的红硒和灰硒。采用恒电势电沉积法在碳纸上直接电沉积Co-Se化合物作为氧还原催化剂,首先对Co-Se的电沉积过程进行了研究,分析了Co-Se在水溶液中的共沉积规律,探究不同扫速对Co-Se共沉积循环伏安行为的影响,分析了电极过程的控制步骤。通过研究主盐浓度、主盐浓度比、沉积电位、温度等工艺条件,得到富硒的具有方硒钴矿结构的CoSe2化合物,并对其形貌、组成、结构及氧还原性能进行研究。结果表明,在碱性或酸性电解液中均具有良好的氧还原催化活性和催化稳定性。该方法制备的CoSe2化合物用作燃料电池氧还原催化剂具有成本低、催化性能好、稳定性高等优点,有望在商用燃料电池中应用。
[Abstract]:Fuel cell is a kind of green power plant which directly converts the chemical energy stored in the fuel into electric energy by electrochemical reaction. In order to solve the problem of high cost, Co-Se compounds have strong catalytic ability for oxygen reduction. The synthesis of Co-Se compounds by electrodeposition can directly electrodeposit the catalyst onto the active site of the membrane electrode, which can greatly improve the utilization rate of the catalyst. And there are few researches on the electrodeposition of oxygen reduction catalysts for fuel cells, so the electrodeposition of oxygen reduction catalysts for Co-Se compounds has been studied in this paper. At first, the electrodeposition of se thin films on copper substrates was carried out by potentiostatic electrodeposition. The electrochemical behavior of se was studied in aqueous solution with the main salt as SeO2. The results showed that the deposition process of se was divided into three steps, and the reduction of se by four electrons was first observed. The six electron reduction of se and the chemical reduction of se on the surface of the electrode occurred again. The effects of deposition potential, concentration of main salt and temperature and pH on the morphology and structure of se films were investigated. Red selenium and grey selenium with monoclinic and hexagonal structure were obtained at 20 鈩，

本文编号：1803235