报告人：高峰

美国Southern University 物理与数学学院

报告时间：2017年12月20日（星期三）上午9：00

报告地点：知新楼C1011

邀请人：彭勇刚 博士

教育及工作经历：

2004 — 2007

Atomic and Molecular Physics,

School of Physics and Electronic Engineering, Ludong University, Yantai, China

2008 --- 2011

Condensed Matter Physics

School of Physics, Shandong University, Jinan, China

2011 --- 2015

Department of Mathematics and Physics, Southern University and A & M College, Baton Rouge, LA, USA

2016 --- Present

Assistant Professor

Department of Mathematics and Physics, Southern University and A & M College, Baton Rouge, LA, USA

摘要：

Recent experimental reports proposed that pyridinic-type sites on the open-edges of carbon nanotubes (CNTs) may contribute to the high catalytic activity for oxygen reduction reation (ORR) on nitrogen-doped CNTs (N-CNTs), Herein, we performed first-principles spin-polarized density functional theory (DFT) calculations to examine the catalytic steps for ORR and water formation reaction (WFR) on the open-edges of N-CNTs. For half N doping on the open-edge of CNTs (HN-CNTs), O2 and OOH can be chemisorbed and partially reduced on the C-N bridge site without an energy barrier. The subsequent WFR for reduced O2/OOH with ambient H+ and additional electrons can be finished without energy battier for the formation of two H2O molecules. The second H2O molecule needs an energy of about 0.49 eV to be desorbed from the catalytic site that complete and electrocatalytic reaction cycle on the cathode catalyst for hydrogen fuel cells (HFCs). For H saturated open edge sites of HN-CNT. ORR and WFR can also be completed energetically. For full N doping on the open-edge of CNTs (FN-CNTs), O2 can be reduced and dissociated on the N-N bridge site with an energy battier of 0.81 eV during the ORR. The WFR steps can then be finished spontaneously. OOH can also be adsorbed and reduced on the N-N bridge site of FN-CNTs; and the subsequent WFR steps can be completed spontaneously. The rate-limiting steps for the full electrocatalytic reactions on N-CNTs as cathode catalyst for HFCs are determined.