title: Residual metallic impurities within carbon nanotubes play a dominant role in supposedly "metal-free" oxygen reduction reactions.
abstract: Oxygen reduction reactions (ORRs) are of key importance in the area of electrochemical energy production. The replacement of the Pt industrial standard with heteroatom doped metal-free carbon nanotubes was previously suggested for ORRs. Here we will show that the ORR electrocatalysis on these supposedly metal-free materials is likely in fact due to the presence of residual metallic impurities within the carbon nanotubes and that these impurities play a dominant role.
authors.affiliation: Division of Chemistry & Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore. pumera@ntu.edu.sg pumera.research@gmail.com.
authors.forename: Lu
authors.initials: L
authors.lastname: Wang
authors.forename: Martin
authors.initials: M
authors.lastname: Pumera