Abstract:

Electrochemical oxygen reduction reaction (ORR) is key to clean and sustainable energy technologies including proton exchange membrane fuel cells and metal-air batteries. However, the high-activation barriers in ORR often makes it the bottleneck of energy conversion processes, and thus high performance ORR electrocatalysts are desired. At present the best commercially available ORR catalyst is based on the precious metal Pt. But it suffers from resource scarcity and unsatisfactory operational stability, thus hindering a widespread and large-scale application of the clean and sustainable technologies. To tackle this problem, extensive efforts have been made in the last decade or so to search after efficient non-precious metal ORR catalysts. Among these, many heteroatoms-doped carbon (HDC) materials appear to be very promising, owing to their easy availability, low cost and excellent electrochemical performance. In this review article, recent advances in this active area are summarized, with the content being categorized according to the different underlying mechanisms of doped heteroatoms. Theoretical and experimental findings regarding HDC materials in ORR catalysis are reviewed, emphasizing the influence of heteroatom doping on the electronic structure of carbon materials. The problems facing HDC based ORR catalysts and further researches required are also discussed.

Key words: oxygen reduction reaction, heteroatom doping, electrocatalysts, electronic materials, catalysis, electrochemistry

摘要：

氧还原反应（ORR）是质子交换膜燃料电池和金属空气电池等清洁能源转化技术中的关键步骤，但其反应能垒高，动力学缓慢。目前，氧还原性能最佳的催化剂仍然是已经商业化的碳载铂（Pt/C）催化剂，但其价格高、资源储量低，难以大规模应用。因此，近年来许多研究者致力于探寻低成本高性能非铂ORR催化剂，以期降低催化剂成本，推进质子交换膜燃料电池和金属空气电池的商业化进程。杂原子掺杂碳材料属于一种新型的非贵金属ORR催化剂，具有优异的电化学性能且成本低廉，显示了广阔的应用前景。以杂原子的不同作用原理为线索综述最近几年杂原子掺杂碳基ORR催化剂的研究进展，着重论述杂原子对于碳材料电子结构的影响，并讨论了杂原子掺杂碳材料催化剂面临的问题以及发展趋势。

关键词: 氧还原反应, 杂原子掺杂, 电催化剂, 电子材料, 催化, 电子学