Rivera Gavidia Luis M, Sebastián David, Pastor Elena, Aricò Antonino S, Baglio Vincenzo
Departamento de Química, Instituto de Materiales y Nanotecnología, Universidad de La Laguna, Avda. Astrofísico Francisco Sánchez s/n, La Laguna, Santa Cruz de Tenerife 38200, Spain.
Istituto di Tecnologie Avanzate per l'Energia "Nicola Giordano", CNR. Via Salita S. Lucia sopra Contesse 5, Messina 98126, Italy.
Materials (Basel). 2017 May 25;10(6):580. doi: 10.3390/ma10060580.
Direct methanol fuel cells (DMFCs) are electrochemical devices that efficiently produce electricity and are characterized by a large flexibility for portable applications and high energy density. Methanol crossover is one of the main obstacles for DMFC commercialization, forcing the search for highly electro-active and methanol tolerant cathodes. In the present work, carbon-supported Pd and PdFe catalysts were synthesized using a sodium borohydride reduction method and physico-chemically characterized using transmission electron microscopy (TEM) and X-ray techniques such as photoelectron spectroscopy (XPS), diffraction (XRD) and energy dispersive spectroscopy (EDX). The catalysts were investigated as DMFC cathodes operating at different methanol concentrations (up to 10 M) and temperatures (60 °C and 90 °C). The cell based on PdFe/C cathode presented the best performance, achieving a maximum power density of 37.5 mW·cm at 90 °C with 10 M methanol, higher than supported Pd and Pt commercial catalysts, demonstrating that Fe addition yields structural changes to Pd crystal lattice that reduce the crossover effects in DMFC operation.
直接甲醇燃料电池（DMFC）是一种能高效发电的电化学装置，其特点是在便携式应用中具有很大的灵活性和高能量密度。甲醇渗透是DMFC商业化的主要障碍之一，这促使人们寻找具有高电活性和耐甲醇性能的阴极。在本工作中，采用硼氢化钠还原法合成了碳载钯和钯铁催化剂，并利用透射电子显微镜（TEM）以及光电子能谱（XPS）、衍射（XRD）和能量色散光谱（EDX）等X射线技术对其进行了物理化学表征。研究了这些催化剂作为DMFC阴极在不同甲醇浓度（高达10 M）和温度（60℃和90℃）下的性能。基于钯铁/碳阴极的电池表现出最佳性能，在90℃、甲醇浓度为10 M时实现了37.5 mW·cm的最大功率密度，高于负载型钯和铂商业催化剂，表明添加铁会使钯晶格发生结构变化，从而降低DMFC运行中的渗透效应。
