可溶性酚醛树脂为碳源合成有序介孔炭及其电催化性能

Synthesis and electrocatalytic performance of ordered mesoporous carbons produced by a hard templating method using phenolic resol as carbon precursor

利用介孔硅SBA-15与苯酚、甲醛混合,原位合成可溶性酚醛树脂,高温炭化得有序介孔炭(C1);同时将预聚的酚醛树脂与SBA-15共混后再聚合,高温炭化得有序介孔炭(C2)。微波多元醇还原法合成Pt/C1、Pt/C2、Pt/CMK-5(糠醇为碳源)电催化剂。使用X射线衍射仪(XRD),N2物理吸附,透射电镜(TEM)和循环伏安技术(CV)对介孔炭的结构和催化剂的性能进行了表征。结果表明:C1主要由规则的六方介孔孔道构成,比表面积为947m2/g,孔径分布集中在4.5nm,Pt微粒在C1上具有良好的分散性,平均粒径约为3nm。C2的孔道较为模糊,负载的Pt微粒有一定程度的团聚。CV曲线显示,Pt/C1催化剂的电化学活性面积(EAS)为54.2m2/g,其催化甲醇氧化的性能优于Pt/C2及Pt/CMK5-而略差于商用催化剂Pt/C(E-TEK)。

Ordered mesoporous carbons （OMC） were prepared by high temperature carbonization of in,situ synthesized phenolic resol from phenol and formaldehyde within ordered mesoporous silica SBA-15 and of mixture of SBA-15 and phenolic resol prepared in advance. These are denoted C1 and C2 respectively. Pt/C1, Pt/ C2 and Pt/CMK-5 （furfural as carbon precursor） electrocatalysts were prepared by a microwave-assisted polyol process. The microstructure of the samples was characterized by XRD, TEM and nitrogen adsorption. The performance of Pt loaded samples for methanol electrooxidation was characterized by cyclic voltammetry （CV）, Results show that C1 has an ordered hexagonal （P6 mm symmetry） mesoporous structure with a BET surface area of 947 m^2/g and a sharp pore size distribution around 4.5 nm. The Pt nanoparticles are uniformly dispersed on C1 with an average diameter of 3 nm, while for. C2 the pores are somewhat disordered and the Pt nanoparticles Re agglomerated. The CV curves indicate that Pt/C1 exhibits a higher electrocatalytic activity for methanol electrooxidation than do Pt/C2 and Pt/CMK-5 and a little bit lower activity than does commercial E-TEK Pt/C. The electrochemically active surface area of Pt/C1 is 54.2 m^2/g.