氮掺杂MnCo2O4/N-KB的制备及氧还原催化性能

以Mn(Ac)_2和Co(Ac)_2作为前驱体,导电碳Ketjenblack (KB)作为负载碳源,采用水解-水热法制备氮掺杂的MnCo_2O_4/N-KB催化剂材料,对其结构特征和碱性溶液中氧还原反应的催化性能进行表征,并进一步分析其氧还原反应活性。结果表明:MnCo_2O_4/N-KB催化剂的形态是KB骨架上生长纳米级MnCo_2O_4,并且在N-KB和MnCo_2O_4之间形成化学耦合,产生协同作用,有效提高了MnCo_2O_4/N-KB催化剂的氧还原活性。MnCo_2O_4与N-KB的质量比为1∶9时,MnCo_2O_4/N-KB催化剂在O_2饱和0.1mol·L~(-1)KOH溶液中对氧还原反应的电催化性能最佳,反应的极限电流密度为5.7 mA·cm~(-2),半波电位接近0.81 V,电子转移数为4。在相同负载量下,MnCo_2O_4/N-KB催化剂相比商用Pt/C(电流密度5.2 mA·cm~(-2),半波电位0.83 V)有着更高的极限电流密度和耐久性。

Preparation and Catalytic Performance for Oxygen Reduction of Nitrogen Doped MnCo2O4/N-KB

MnCo₂O₄/N-KB catalysts was prepared by hydrolysis-hydrothermal method, in which Mn(Ac)2 and Co(Ac)2 were used as precursors and nitrogen doped conductive carbon Ketjenblack (KB) was used as the carbon source. The microstructure of the MnCo₂O₄/N-KB catalysts and its catalytic performance for oxide reduction reaction were studied. The results showed that chemical coupling was formed between N-KB and MnCo₂O₄. It produced synergistic effect and effectively improved the oxygen reduction activity of MnCo₂O₄/N-KB catalyst. When the mass ratio of MnCo₂O₄ to N-KB was 1:9, the limiting current density of the reaction was 5.7 mA·cm^-2 and the half wave potential was close to 0.81 V. MnCo₂O₄/N-KB catalyst obtained the best electrocatalytic performance for oxygen reduction. Comparing to the commercial Pt/C catatlyst with a current density of 5.2 mA·cm^-2 and a half-wave potential 0.83 V, MnCo₂O₄/N-KB catalyst had a highly active oxygen reduction with higher ultimate current density and durability under the same capacity condition.