双中心MOFs衍生的Co-ZnO@CN纳米材料作为电化学催化剂用于氧还原反应的研究

采用水热法合成了一系列的Co-Zn-MOF材料,随后将其在高温下热解,采用自模板的方式得到双中心MOFs衍生的Co-ZnO@CN纳米催化剂.通过调节前驱体的比例和热解温度,优化了制备Co-ZnO@CN纳米催化剂的条件.利用粉末X射线衍射(XRD)和X射线光电子能谱(XPS)对Co-ZnO@CN纳米催化剂的结构及表面化学性质进行表征,采用扫描电子显微镜(SEM)和能量色散谱仪(EDS)考察了Co-ZnO@CN纳米催化剂的形貌和表面化学元素的种类和组成.通过氧还原反应(ORR)测试了催化剂的催化性能.实验结果表明当热解温度为800℃,Co与Zn摩尔质量之比为1∶2时,所得到的Co-ZnO(1∶2)@CN-800纳米催化剂的催化活性最高,其起始电势和半波电势分别为0.90和0.78 V,此外,通过计算表明该纳米催化剂在氧还原反应中氧分子还原过程遵循4e-反应路径.

Bi-centered MOFs-derived Co-ZnO@CN Nano-material as Efficient Electrocatalyst for Oxygen Reduction Reaction

A series of Co-Zn-MOF materials are synthesized by using hydrothermal method, then these materials are employed as self-templates to synthesize non-precious bi-centered MOFs-derived Co-ZnO@CN alloy nanocatalysts at high temperatures. The preparation conditions of Co-ZnO@CN materials are optimized by adjusting the molar ratio of precursor and thermolysis temperatures. The XRD and XPS are employed to characterize the structures and surface chemical state of Co-ZnO@CN catalysts, and the SEM and EDS are employed to analyze the morphology and the components of Co-ZnO@CN catalysts, and then these materials are used for ORR to test the catalytic performance. The experimental results indicate that Co-ZnO(1:2)@CN-800 exhibits the optimal activity toward ORR, the onset and half-wave potential of Co-ZnO(1:2)@CN-800 are 0.90 and 0.78 V, respectively. Moreover, The calculation indicates that the reduction of oxygen molecules follow the 4e^- route on this catalyst.