Cu nanoclusters on N-doped carbon nanotubes as efficient electrocatalyst for oxygen reduction reaction

Earth-rich transition metal-based catalysts are considered to be the most promising candidates to alternate noble metal-based electrocatalysts for oxygen reduction reaction (ORR). Nevertheless, the practical applications have been hampered due to their poor electrocatalytic behaviors and stability. Here, we report the facial thesis of Cu nanoclusters supported on N-doped carbon nanotubes by a simple grinding and heat treatment method, which presented a superior electrocatalytic performance than commercial Pt/C. In alkaline media, an onset potential (E 0 ) and half-wave potential (E 1/2 ) of 0.98 V and 0.88 V (RHE) have been achieved, respectively. In addition, the synthesized catalysts present a good tolerance and long-term stability to methanol, and exhibit less than 7% H 2 O 2 formation. It is inferred that the enhanced electrocatalytic behavior could be attributed to the formation of Cu-N X active sites, which are coupled into the nitrogen-rich carbon nanotubes. This low-cost, extremely durable and stable electrocatalyst showed a great potential as an efficient cathode material for a variety of renewable energy conversion technologies, such as fuel cells and metal-air cells.