以六水合硝酸钴为金属源,苯并咪唑为有机配体,对苯二胺改性氧化石墨烯(PGO)为碳载体,采用一步溶剂热法合成金属有机骨架(MOF)-PGO前躯体,经过高温处理制备了多孔Co-N-PGO催化剂。采用比表面积孔隙度分析仪、扫描电子显微镜、透射电子显微镜、X射线衍射、拉曼光谱和X射线光电子能谱等物理表征手段对催化剂形貌、结构以及元素形态进行表征,同时利用线性扫描伏安法和计时电流法对催化剂在碱性电解液中的氧还原(ORR)性能进行测试。结果表明,Co-N-PGO催化剂具有较高的比表面积和电化学活性面积,良好的结晶程度以及丰富的孔洞结构。此外,Co-N-PGO催化剂表现出优异的ORR催化活性,半波电位与商业Pt/C催化剂相比仅相差10mV,同时拥有更好的稳定性及抗甲醇毒化性能。根据K-L方程,Co-N-PGO催化剂在ORR过程中主要为四电子途径,与Pt/C催化剂反应机理相似。
The Co-N-PGO catalyst was obtained by high temperature heat treatment of MOF-PGO,which was synthesized by one-step solvothermal method using p-phenylenediamine functionalized graphene oxide (PGO) as the support,Co(NO3)2 as the metal source and benzimidazole as an organic ligand.The structure of catalysts were characterized by BET,SEM,TEM,XRD,Raman and XPS.At the same time,the oxygen reduction reaction (ORR) performance of catalysts in alkaline electrolyte was investigated by the linear sweep voltammetry (LSV) and the chronoamperometry.The results showed that Co-N-PGO catalyst was highly crystalline with large specific surface area,electrochemical active area and abundant pore structure.In addition,Co-N-PGO catalyst exhibited excellent stability,resistance toward methanol and ORR catalytic activity,which was only 10mV different from commercial Pt/C catalyst at half-wave potential.According to K-L equation,Co-N-PGO catalyst was dominated by a 4-electron transfer process,which was similar to Pt/C catalyst reaction mechanism.
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基金资助
研究生创新基地(实验室)开放基金(KFJJ20160611);江苏高校优势学科建设工程资助项目
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