热解温度对MOFs衍生的ZnO@CN纳米催化剂氧还原性能的影响

Influences of pyrolysis temperature on reduction performances of MOFs-derived ZnO@CN nano catalyst

通过水热法合成Zn-MOF材料,并将其高温热解制备得到Zn O@CN纳米催化剂。通过X射线衍射谱、扫描电子显微镜表征了Zn O@CN的结构和组成。为了探究热解温度对Zn O@CN催化性能的影响,将制得的Zn-MOF材料在不同温度下热解分别得到Zn O@CN-600、Zn O@CN-700、Zn O@CN-800、Zn O@CN-900,通过氧还原反应测试其催化活性。结果表明,热解温度为900℃时制得的Zn O@CN-900起始电势和半波电势分别为0.890 V和0.780 V。动力学研究结果表明,Zn O@CN-900的电子转移数约为4,证明氧气分子在Zn O@CN-900催化剂表面还原采用四电子路径。

Zn-MOF material is synthesized by using hydrothermal method,and then is pyrolyzed at high temperature to prepare nitrogen-doped carbon nano catalysts（ZnO@CN）. The structure and composition of ZnO @ CN catalyst are analyzed and characterized by XRD and SEM. In order to investigate the effect of pyrolysis temperature on the catalytic performance of ZnO@CN,the prepared Zn-MOF materials are pyrolyzed at different temperatures to prepare a series of catalysts： ZnO@CN-600,ZnO @ CN-700,ZnO @ CN-800,ZnO @ CN-900. Subsequently,the catalytic activities of these catalysts are tested by the reduction reaction of oxygen.The experimental results indicate that ZnO@CN-900 prepared at900℃ exhibits optimal catalytic activity with the onset potential at 0. 89 V and half-wave potential at 0. 78 V.In addition,the kinetic studies show that the electron transfer number of ZnO@CN-900 is around 4,which verifies that the reduction process of oxygen molecular on the surface of ZnO@CN-900 employs a four-electron pathway.