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-N-x-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, MM[1];Fan, MM[2];Wu, YC[3];Sun, DP[4];Jiang, JC[5]

机构：[1]Nanjing Forestry Univ, Coll Chem Engn, Jiangsu Coinnovat Ctr Efficient Proc & Utilizat F, Nanjing 210037, Peoples R China;[2]Rice Univ, Dept Mat Sci & NanoEngn, Houston, TX 77005 USA;[3]Hefei Univ Technol, Sch Mat Sci & Engn, Hefei 230009, Peoples R China;[4]Univ Cincinnati, Dept Chem & Environm Engn, Cincinnati, OH 45221 USA;[5]Univ Sci & Technol China, CAS Ctr Excellence Nanosci, Natl Synchrotron Radiat Lab, Hefei 230026, Peoples R China;[6]Nanjing Univ Sci & Technol, Chemicobiol & Funct Mat Inst, Nanjing 210094, Peoples R China;[7]Chinese Acad Forestry, Jiangsu Coinnovat Ctr Efficient Proc & Utilizat F, Inst Chem Ind Forest Prod, Key Lab Biomass Energy & Mat, Nanjing 210042, Jiangsu, Peoples R China

年份：2021

卷号：91

起止页码：160-167

外文期刊名：JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000697677400006)】；

基金：This work was financially supported by the National Natural Science Foundation of China (Nos. 51572124 and 51702162) , the Natural Science Foundation of Jiangsu Province (No. BK20180154 and BK20180490) , the Fundamental Research Funds for the Central Universities (No. 30920130111003) and A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD, China) .

语种：英文

外文关键词：Modulating effect; N coordination; Single-atom catalysts; Pt-N-x-C model; DFT simulation

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-N-x-C structure (1 <= x <= 4). The M-N-4-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-N-x-C structure and the corresponding catalytic properties. Herein, atomically dispersed Pt on N-doped carbon (Pt-NC) with Pt-N-x-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-N-x-C structure. The Pt-NC has the predictable low half-wave potential (E-1/2) 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 cm(2)) 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. (C) 2021 Published by Elsevier Ltd on behalf of Chinese Society for Metals.