文献类型：期刊文献

英文题名：The modulating effect of N coordination on single-atom catalysts researched by Pt-Nx-C model through both experimental study and DFT simulation

作者：Fan, Mengmeng[1,2] Cui, Jiewu[2,3] Zhang, Junjie[2] Wu, Jingjie[4] Chen, Shuangming[5] Song, Li[5] Wang, Zixing[2] Wang, Ao[7] Vajtai, Robert[2] Wu, Yucheng[3] Ajayan, Pulickel M.[2] Jiang, Jianchun[7] Sun, Dongping[6]

第一作者：Fan, Mengmeng

通信作者：Fan, Mengmeng

机构：[1] Nanjing Forestry University, Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing, 210037, China; [2] Rice University, Department of Materials Science and NanoEngineering, Houston, TX, 77005, United States; [3] Hefei University of Technology, School of Materials Science and Engineering, Hefei, 230009, China; [4] University of Cincinnati, Department of Chemical and Environmental Engineering, Cincinnati, OH, 45221, United States; [5] University of Science and Technology of China, National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, Hefei, 230026, China; [6] Nanjing University of Science and Technology, Chemicobiology and Functional Materials Institute, Nanjing, 210094, China; [7] Key Lab of Biomass Energy and Material, Jiangsu Province, Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry, Nanjing, 210042, China

年份：2021

卷号：91

起止页码：160-167

外文期刊名：Journal of Materials Science and Technology

收录：EI(收录号：20212010363243);Scopus(收录号：2-s2.0-85105750388)

语种：英文

外文关键词：Carbon - Oxygen - Carbonization - Doping (additives) - Electrolytic reduction - Free energy - Atoms - Platinum

摘要：N-doped carbon-based single-atom catalysts (NC-SACs) are widely researched in various electrochemical reactions due to high metal atom utilization and catalytic activity. The catalytic activity of NC-SACs originates from the coordinating structure between single metal site (M) and the doped nitrogen (N) in carbon matrix by forming M-Nx-C structure (1≤ x≤ 4). The M-N4-C structure is widely considered to be the most stable and effective catalytic site. However, there is no in-depth research for the "x" modulation in Pt-Nx-C structure and the corresponding catalytic properties. Herein, atomically dispersed Pt on N-doped carbon (Pt-NC) with Pt-Nx-C structure (1≤ x≤ 4), as a research model, is fabricated by a ZIF-8 template and applied to catalytic oxygen reduction. Different carbonization temperatures are used to control N loss, and then modulate the N coordination of Pt-Nx-C structure. The Pt-NC has the predictable low half-wave potential (E1/2) of 0.72 V vs RHE compared to the Pt/C 20% of 0.81V due to low Pt content. Remarkably, the Pt-NC shows a high onset potential (1.10 V vs RHE, determined for j = -0.1 mA cm2) and a high current density of 5.2 mA cm?2, more positive and higher than that of Pt/C 20% (0.96 V) and 4.9 mA cm?2, respectively. As the structural characterization and DFT simulation confirmed, the reducing Pt-N coordination number induces low valence of Pt atoms and low free energy of oxygen reduction, which is responsible for the improved catalytic activity. Furthermore, the Pt-NC shows high mass activity (172 times higher than that of Pt/C 20%), better stability and methanol crossover resistance. ? 2021