在Pt/CNTs催化层中预混-溶解La2O3颗粒来构筑孔结构促进甲醇电氧化

为认识孔隙度增加对甲醇电氧化的影响, 将熔盐法制备的La2O3颗粒与Pt/CNTs(碳纳米管)预混合然后用HClO4溶掉La2O3颗粒, 从而增加了Pt/CNTs催化层的孔隙度. 扫描电子显微镜(SEM)观察表明, 该处理可以形成孔结构. 用循环伏安和计时电流实验考察了孔隙度增加对甲醇电氧化的影响, 结果表明甲醇电氧化电流可增加57%. 分析认为, 电流增加的原因是由于多孔催化层中甲醇更易于到达Pt催化剂表面进行电氧化. 该研究表明, 通过在催化层中预混-溶解La2O3来增加孔隙是一种改善催化层性能的有效方法.

Promoting Methanol Electro-Oxidation through Fabricating Pore Structure in Pt/CNTs Catalyst Layer by Dissolving Away Premixed La2O3 Particles

To gain insight into the effect of increasing porosity on methanol electro-oxidation, La2O3 particles prepared throughmolten salt method were introduced into a Pt/carbon nanotubes (CNTs) catalyst layer and then dissolved in HClO4, which increased the porosity in the Pt/CNTs catalyst layer. The existence of the as-formed pore structures was confirmed by scanning electronic microscopy (SEM). Cyclic voltammetry (CV) and chronoamperometry methods were used to investigate the effect of increasing porosity, which showed that the methanol electro-oxidizing current was enhanced by 57%. The reason for this result is ascribed to improved methanol access to the Pt surface in the porous catalyst layer. The results indicate that the fabrication of pores in catalyst layer by dissolving away premixed La2O3 particles is an effective method to promote catalyst layer performance.