Effect of Pt-Mn nanoparticles supported on CNT in methanol electro-oxidation reaction, experimental, and theoretical studies

This work reports the facile synthesis of Pt-Mn nanoparticles supported on multiwall carbon nanotubes using the Brust-Schiffrin method and their electrochemical performance during methanol electro-oxidation reaction. According to the topographical and structural results, the Pt-Mn nanoparticles present high dispersion with a narrow size distribution of similar to 2.5 nm. Meanwhile, the electrochemical evaluation exhibits a greatly enhanced electrocatalytic activity. The electrocatalyst's performance improves as Mn increased up to 40 at.% in Pt nanoparticles, but it decreases as Mn reaches 50 at.%. The electrocatalytic activity fall could be attributed to a reduction on active sites favorable to the dissociation and dehydrogenation of methanol. Density functional theory computations reveal that the partial density of states (PDOS) associated with [Mn]3d orbitals could be directly correlated with the observed electrocatalytic behavior. The respective maximum PDOS contribution at the Fermi level also corresponds to the most active electrocatalyst, which contains Mn of similar to 40 at.%.

Automated summary

This study reports the facile synthesis of Pt-Mn nanoparticles supported on multiwall carbon nanotubes, showing that the electrocatalyst performs best at 40at.% Mn and decreases at 50at.% Mn. Density functional theory computations reveal a correlation between the partial density of states associated with [Mn]3d orbitals and the observed electrocatalytic behavior.