Ultrathin TiO2-coated MWCNTs with excellent conductivity and SMSI nature as Pt catalyst support for oxygen reduction reaction in PEMFCs

Abstract

The sluggish kinetics of the oxygen reduction reaction (ORR), the instability of platinum on the carbon support, and carbon corrosion are still critical issues affecting the activity and long-term durability of polymer electrolyte membrane fuel cells. An ideal solution would be to modify the catalytic supports to enhance the durability and performance of supported catalysts. Here we have synthesized multiwalled carbon nanotube (MWCNT) supported ultrathin TiO₂ films (MWCNT@UT-TiO₂) using a simple modified sol–gel method. Our approach takes advantage of the strong metal support interactions (SMSIs) between the MWCNT@UT-TiO₂ support and platinum nanoparticles, which results in a decrease of the d-band vacancy of platinum due to electron transfer from the support, thereby enhancing the performance of the supported catalysts. Our results revealed that Pt–MWCNT@UT-TiO₂ has better catalytic activity and durability compared to Pt–MWCNT and Pt–C with equivalent Pt loadings.