Enhanced electrocatalytic activity of platinum nanoparticles supported on nitrogen-modified mesoporous carbons for methanol electrooxidation
Enhanced electrocatalytic activity of platinum nanoparticles supported on nitrogen-modified mesoporous carbons for methanol electrooxidation
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DOI：
10.1016/j.ijhydene.2015.01.014
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发表时间：
2015-02-23
影响因子：
7.2
通讯作者：
Chen, Zhidong
中科院分区：
文献类型：
--
作者：
Cao, Jianyu;Yin, Xiaojuan;Chen, Zhidong
以酚醛聚合物为碳源，双氰胺为氮源，二氧化硅纳米球为硬模板，三嵌段共聚物F127为软模板，采用改进的双模板法合成了氮修饰介孔碳（N-MCs）。结构表征表明，具有大介孔和均匀介孔网络的N-MCs具有三种不同的含氮基团，均可作为催化活性位点。采用多元醇还原法制备了N-MCs负载铂纳米粒子（Pt/N-MCs）。透射电镜（TEM）显示，纳米Pt颗粒均匀分布在N-MCs的孔壁上，平均粒径约为2.0 nm，远小于商用Pt/C。电化学研究表明，Pt/N-MCs比Pt/MCs和商品Pt/C具有更高的甲醇氧化电催化活性，这可能是由于吡啶氮和吡啶氮向sp(2)杂化石墨碳层提供p电子，导致内部电阻降低，质子扩散速率加快，并且Pt在N-MCs上的粒度分布更加均匀。版权所有，氢能源出版有限责任公司，爱思唯尔有限公司出版。版权所有。
Nitrogen-modified mesoporous carbons (N-MCs) are synthesized via a modified dual-templating approach, in which phenolic polymer is used as a carbon source, dicyandiamide as a nitrogen source, silica nanospheres as a hard template, and triblock copolymer F127 as a soft template, respectively. Structural characterizations reveal that the N-MCs with large mesopore and uniform mesoporous networks possess three different nitrogen-containing groups, all of which can serve as catalytically active sites. Platinum nano-particles supported on N-MCs (Pt/N-MCs) are prepared by polyol reduction method. As supported by transmission electron microscopy (TEM), homogeneously dispersed Pt nanoparticles are attached to the pore wall of N-MCs with an average size of ca. 2.0 nm, much smaller than that of commercial Pt/C. Electrochemical studies reveal that the Pt/N-MCs has higher electrocatalytic activities for methanol oxidation in comparison to the Pt/MCs and commercial Pt/C, which may be attributed to pyridinic and pyrrolic nitrogen offering p electrons to the sp(2) hybridized graphitic carbon layers, leading to the decrease of inner electrical resistance and enhanced proton diffusion rate, as well as a more uniform particle size distribution of Pt on N-MCs. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.