微型多孔材料
限制电流
碳纤维
催化作用
电化学
传质
多孔性
化学工程
活性炭
烧焦
化学
氧气
电子转移
材料科学
无机化学
多孔介质
热解
电极
复合材料
有机化学
吸附
色谱法
物理化学
工程类
复合数
作者
Atsushi Gabe,Ramiro Ruíz-Rosas,Carolina González-Gaitán,Emilia Morallón,Diego Cazorla‐Amorós
标识
DOI:10.1016/j.jpowsour.2018.11.075
摘要
The role of porosity, and more specifically, microporosity, in the performance of carbon materials as Oxygen Reduction Reaction (ORR) catalysts in alkaline medium still has to be clarified. For this purpose, a highly microporous KOH-activated carbon and a microporous char have been prepared and their ORR performance in alkaline media were compared to that of two commercial carbon blacks with low and high surface areas, respectively. Interestingly, all carbon materials show a two-wave electrocatalytic process, where the limiting current and the number of electron transferred increase when going to more negative potentials. The limiting current and onset potential of the second wave is positively related to the amount of microporosity, and H2O2 electrochemical reduction tests have confirmed that the second wave could be related to the catalytic activity towards this reaction. In accordance to these findings, a model is developed that takes into account narrow and wide micropores in both charge transfer reactions and the mass transfer rate of O2 and H2O2. This model successfully reproduces the experimental electrochemical response during ORR of the analyzed porous carbon materials and suggests the important role of narrow micropores in H2O2 reduction.
科研通智能强力驱动
Strongly Powered by AbleSci AI