摘要
随着能源的快速消耗,燃料电池已经成为新型能源中非常重要的一部分。Pt/C被广泛应用于燃料电池的电极负极中,但是,由于Pt/C具有耐久性差、甲醇交叉效应、CO中毒等特性,制约着燃料电池在能源方面的快速发展,因此,我们需要开发一种新型非贵金属催化剂材料来代替Pt/C。采用"活性硬模板"方法,以钴球作为模板,多巴胺和Fe3+螯合后包覆在钴球表面,经过高温退火和酸处理后得到铁钴双掺杂的具有中空碳球结构的(Fe,Co)-N-C催化剂。在制备过程中,钴球不仅为(Fe,Co)-N-C催化剂提供钴离子源,同时又为催化剂提供球形结构,使得催化剂具有大比表面积,增加活性位点与电解质的接触面。钴铁的双掺杂使得(Fe,Co)-N-C催化剂含有大密度的活性位点,而且当多巴胺退火形成的碳将钴离子还原成钴颗粒并镶嵌在碳层中,形成的钴颗粒比碳具有更高的活性中心,使得活性位点更有利于氧还原反应(ORR)电子转移,且经过测试发现,其半波电位接近于商业化Pt/C,具有出色的电催化性能。
Full cell is generally believed to be an important part among various new energy resources with the rapid energy consumption. Pt/C has been extensively applied in cathodes of full cells, the emerging progress of which, however, is seriously restricted by the poor durability, cross effect of methanol, carbon monoxide poisoning of Pt/C. Herein, much effort should be devoted towards the development of new non-noble metal catalysts that can replace Pt/C. The ＂active hard template＂ method is employed. Specifically, the as-chelated dopamine and Fe3＋ are coated on the surface of cobalt sphere which acts as template, hollow carbon sphere structure with iron and cobalt co-doping can be achieved after high-temperature annealing and acid treatment. During the preparation process, the cobalt sphere template provides cobalt ion and simultaneously the sphere structure for （Fe, Co）-N-C catalyst, thus contributing to large specific surface area, that is, increasing the contact area between active sites and electrolyte. The co-doping of iron and cobalt is favorable for the acquisition of active sites with large density in the the （Fe, Co）-N-C catalyst. Additionally, the formation of carbon after dopamine annealing enables the reduction of cobalt ion into cobalt particles, which are then embedded in carbon layer, the cobalt particles present higher active center than carbon, by virtue of which ORR electron transfer becomes more feasible. The test result show that the half-wave potential is in close proximity performance. to that of Pt/C, thereby indicating excellent electrocatalytic
出处
《安徽化工》
CAS
2018年第1期69-73,77,共6页
Anhui Chemical Industry
关键词
活性硬模板
活性位点
催化性能
reactive hard template
active site
electrocatalytic performance
