用于PEMFC的介孔碳担载铂氧化钨电催化剂的制备与表征

Preparation and characterization of mesoporous carbon supported Pt-WO_3 nanoparticles as electrocatalysts for PEMFC

利用介孔碳作为载体,制备介孔碳担载Pt-WO3复合催化剂应用于质子交换膜燃料电池(PEMFC)电极.以苯为碳源,采用气相沉积法复制介孔SiO2Al-SBA-15模板结构合成石墨化介孔碳Cg,采用浸渍法制备无定形介孔碳CMK-3.通过分步沉积,将Pt和WO3担载到介孔碳载体上,采用比表面分析(BET)、X线衍射(XRD)、透射电子显微镜(TEM)、循环伏安法以及单电池极化性能测试对介孔碳担载的复合催化剂进行表征.结果表明:介孔碳作为催化剂载体,其孔道结构有助于催化剂的均匀分散,从而提高催化剂的电催化剂活性.由于石墨化介孔碳的导电性能高于无定形介孔碳,因此Pt-WO3/Cg比Pt-WO3/CMK-3具有更好的电极催化活性.

Mesoporous carbon supported Pt-WO3 was prepared as electrocatalysts for Proton exchange membrance fuel cell（PEMFC）.Partially graphitic mesoporous carbon（Cg） was synthesized by chemical vapor deposition method.Benzene was deposited in the channels of Al-doped mesoporous silica Al-SBA-15.Furthermore,by a facile one-step impregnation method,ordered amorphous mesoporous carbon CMK-3 was prepared using SBA-15 as template.Pt and WO3 nanoparticles were supported on these two kinds mesoporous carbon by in-situ synthesis method.The graphitic and amorphous mesoporous carbons,serving as Pt-WO3 support,were characterized by X-ray diffraction（XRD）,N2 adsorption-desorption isotherms,transmission electron microscopy（TEM）.The electrocatalysis of Pt-WO3/CMK-3 and Pt-WO3/Cg was determined by cyclic voltammetry and single cell polarization performance.The results indicated that the porous structure of mesoporous canbon benefited the dispersion of electrocatalysts on the support.Therefore,the electrocatalytic activation of the catalysts was increased.Pt-WO3/Cg had higher electrocatalytic activation than Pt-WO3/CMK-3 as an anodic catalyst for PEMFC because of the enhanced electronic conductivity of Cg.