Binary and Ternary Doping of Nitrogen, Boron, and Phosphorus into Carbon for Enhancing Electrochemical Oxygen Reduction Activity
Binary and Ternary Doping of Nitrogen, Boron, and Phosphorus into Carbon for Enhancing Electrochemical Oxygen Reduction Activity
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DOI：
10.1021/nn3021234
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发表时间：
2012-08-01
期刊：
影响因子：
17.1
通讯作者：
Woo, Seong Ihl
中科院分区：
文献类型：
--
作者：
Choi, Chang Hyuck;Park, Sung Hyeon;Woo, Seong Ihl
N-掺杂碳是在酸性介质中用于氧还原反应（ORR）的Pt催化剂的有前景的替代物，通过额外掺杂B和Pat碳生长步骤来改性N-掺杂碳以提高其催化活性。这种额外的掺杂改变了碳的电学、物理和形态学特性。B掺杂增强了石墨的sp（2）-结构，增加了碳晶格中吡啶-N位的比例，而P掺杂增强了碳原子的电荷离域，产生了具有许多边缘位的碳结构。氮掺杂碳的这些电和物理变化更有利于碳表面氧的还原。与N掺杂的碳相比，B、N掺杂的或P、N掺杂的碳在酸性介质中在0.6 V（相对于RHE）下显示出1.2或2.1倍高的ORR活性。反应中活性最高的催化剂是三元掺杂的碳（B，P，N掺杂的碳），在0.6V（vsRHE）下的质量活性为-6.0mA/mg，是N掺杂的碳的2.3倍。这些结果表明，B和P与N的二元或三元掺杂可显著提高碳基催化剂的性能，碳原子的电荷离域或碳的边缘位数是决定碳基催化剂氧还原活性的重要因素。
N-doped carbon, a promising alternative to Pt catalyst for oxygen reduction reactions (ORRs) in acidic media, is modified in order to increase its catalytic activity through the additional doping of B and Pat the carbon growth step. This additional doping alters the electrical, physical, and morphological properties of the carbon. The B-doping reinforces the sp(2)-structure of graphite and increases the portion of pyridinic-N sites in the carbon lattice, whereas P-doping enhances the charge delocalization of the carbon atoms and produces carbon structures with many edge sites. These electrical and physical alternations of the N-doped carbon are more favorable for the reduction of the oxygen on the carbon surface. Compared with N-doped carbon, B,N-doped or P,N-doped carbon shows 1.2 or 2.1 times higher ORR activity at 0.6 V (vs RHE) in acidic media. The most active catalyst In the reaction is the ternary-doped carbon (B,P,N-doped carbon), which records -6.0 mA/mg of mass activity at 0.6V (vs RHE), and it is 2.3 times higher than that of the N-doped carbon. These results imply that the binary or ternary doping of B and P with N into carbon induces remarkable performance enhancements, and the charge delocalization of the carbon atoms or number of edge sites of the carbon is a significant factor in deciding the oxygen reduction activity in carbon-based catalysts.