Spinel-type NiCo2O4 with abundant oxygen vacancies as a high-performance catalyst for the oxygen reduction reaction
Spinel-type NiCo2O4 with abundant oxygen vacancies as a high-performance catalyst for the oxygen reduction reaction
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DOI：
10.1016/j.ijhydene.2019.07.091
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发表时间：
2019-09
影响因子：
7.2
通讯作者：
Dongwook Lim;H. Kong;Chaewon Lim;Namil Kim;S. Shim;S. Baeck
中科院分区：
文献类型：
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作者：
Dongwook Lim;H. Kong;Chaewon Lim;Namil Kim;S. Shim;S. Baeck
采用水热还原和氢气热还原相结合的方法，成功地合成了具有大量氧空位的尖晶石型镍钴氧化物。研究了氧空位对氧还原反应的电化学活性和稳定性的影响。制得的催化剂在碱性条件下表现出明显的氧还原催化性能，与工业铂碳催化剂相当。与可逆氢电极相比，缺氧NiCo2O4表现出很高的极限电流密度−5.44mA/cm−2，起始和半波电位分别为0.93V和0.78nV。此外，它还表现出出色的耐用性和耐甲醇性能。催化剂ORR活性和稳定性的提高可以归因于较大的电化学比表面积、更多暴露的活性中心和丰富的氧空位带来的良好导电性的协同作用。
Spinel-type nickel cobaltite with numerous oxygen vacancies is successfully synthesized by hydrothermal and thermal reduction using hydrogen. The effects of oxygen vacancies on the electrochemical activity and stability for the oxygen reduction reaction are investigated. The prepared catalyst displays significantly enhanced oxygen reduction reaction (ORR) catalytic performance under alkaline conditions, which is comparable to that of commercial Pt/C. The oxygen-deficient NiCo2O4exhibits a very high limiting current density of −5.44 mA cm−2with onset and half-wave potentials of 0.93 and 0.78 V versus the reversible hydrogen electrode (RHE), respectively. Additionally, it shows excellent durability and resistance to methanol. The enhanced ORR activity and stability of the catalyst can be ascribed to the synergistic effects of the relatively large electrochemical surface area, more exposed active sites, and good electrical conductivity derived from abundant oxygen vacancies.