Silver Nanoparticle/Multiwalled Carbon Nanotube Hybrid as an Efficient Electrocatalyst for Oxygen Reduction Reaction in Alkaline Medium

A facile approach is employed to synthesize Ag/MWNTs hybrids by the direct reduction of silver nitrate with presence of MWNTs, where Ag nanoparticles capped with tris(hydroxymethyl)phosphine oxide (d = 2.9 nm) are uniformly deposited on multi‐walled carbon nanotubes. The as‐synthesized Ag/MWNTs hybrids exhibit high catalytic activity toward oxygen reduction, which increases with the loading amounts of Ag nanoparticles. RDE and RRDE analyses further indicate that the Ag/MWNTs hybrids follow the same four‐electron pathway towards oxygen reduction reaction as the Pt/C catalyst, and the Ag/MWNTs hybrid (22.8 wt.%) manifests comparable catalytic activity to the 20% Pt/C catalyst, together with superior long‐term stability and methanol tolerance, demonstrating the potential application on direct methanol fuel cells as an effective oxygen reduction catalyst.