Hybrid Structure of TiO₂-Graphitic Carbon as a Support of Pt Nanoparticles for Catalyzing Oxygen Reduction Reaction

Abstract

The durability of catalysts in fuel cells is a longstanding issue that needs to be resolved. Catalyst stability of the fuel cell has always been a problem, studies are underway to address them. Herein, to address this issue, we synthesize a hybrid structure consisting of SP carbon (SP) as the graphitic carbon and TiO2 as the metal oxide using a microwave method for use as a support for Pt nanoparticles. Anatase TiO2 and Pt nanoparticles with sizes of ~5 and 3.5 ± 1.4 nm, respectively, are uniformly dispersed on a modified graphitic SP carbon support (Pt-TiO2-SP). This supported Pt catalyst exhibits significantly improves durability in the oxygen reduction reaction (ORR). Furthermore, the Pt-TiO2-SP carbon hybrid catalyst manifests superior electrocatalytic stability and higher onset potential in ORR than those exhibited by Pt-SP carbon without TiO2. Pt-TiO2-SP exhibits an activity loss of less than 68 mV after 5000 electrochemical cycles, whereas an activity loss of ~100 mV is observed for Pt-SP carbon in a stability test. These results suggest that the strong metal–support interaction in TiO2-supported Pt catalyst significantly enhances the activity of Pt nanocatalyst.

Keywords

• TiO₂-carbon hybrid
• catalyst support
• durability
• fuel cell
• graphitic carbon