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Full-Text Articles in Mechanical Engineering

Size-Controlled Large-Diameter And Few-Walled Carbon Nanotube Catalysts For Oxygen Reduction, Xianliang Wang, Qing Li, Hengyu Pan, Ye Lin, Yujie Ke, Haiyang Sheng, Mark T. Swihart, Gang Wu Nov 2015

Size-Controlled Large-Diameter And Few-Walled Carbon Nanotube Catalysts For Oxygen Reduction, Xianliang Wang, Qing Li, Hengyu Pan, Ye Lin, Yujie Ke, Haiyang Sheng, Mark T. Swihart, Gang Wu

Faculty Publications

We demonstrate a new strategy for tuning the size of large-diameter and few-walled nitrogen-doped carbon nanotubes (N-CNTs) from 50 to 150 nm by varying the transition metal (TM = Fe, Co, Ni or Mn) used to catalyze graphitization of dicyandiamide. Fe yielded the largest tubes, followed by Co and Ni, while Mn produced a clot-like carbon morphology. We show that morphology is correlated with electrocatalytic activity for the oxygen reduction reaction (ORR). A clear trend of Fe > Co > Ni > Mn for the ORR catalytic activity was observed, in both alkaline media and more demanding acidic media. The Fe-derived N-CNTs exhibited …


Investigation Of Carbon Corrosion Resistance Of Cnt Containing Electrode, Diana Larrabee, William A. Rigdon, Eli Mcpherson, Joshua Sightler, Xinyu Huang Jan 2012

Investigation Of Carbon Corrosion Resistance Of Cnt Containing Electrode, Diana Larrabee, William A. Rigdon, Eli Mcpherson, Joshua Sightler, Xinyu Huang

Faculty Publications

Carbon support corrosion is one of the major degradation mechanisms of polymer electrolyte membrane (PEM) fuel cell. Carbon oxidation occurs in PEM electrode and is accelerated at high potential created by adverse operating conditions and improper distribution of reactants and products [1, 2, 3]. Carbon corrosion can lead to the thinning of the electrode layer and severe performance degradation. The detailed mechanisms of carbon support corrosion induced performance loss are still not fully understood; it is believed that the following events contribute to the decay: (1) structural collapse of the porous electrode due to the loss of carbon; (2) carbon …