Pt/Tin Oxide/Carbon Nanocomposites as Promising Oxygen Reduction Electrocatalyst with Improved Stability and Activity

In this report, a novel nanostructural Pt/SnO2/C catalyst was synthesized by depositing Pt nanoparticles on the SnO2/C surface. X-Ray Diffraction and Transmission Electron Microscopy characterizations showed that Pt nanoparticles with an average size of ∼2.7 nm were uniformly dispersed on the Pt/SnO2/C catalysts. High Resolution Transmission Electron Microscopy images revealed that Pt nanoparticles were bonded with both SnO2 and C at the SnO2/C junctions, forming Pt/SnO2/C triple junction nanostructures in Pt/SnO2/C catalysts. Electrochemical measurements showed that specific activity towards oxygen reduction reaction (ORR) of Pt/SnO2/C catalysts was 2.3 times as high as that of conventional Pt/C catalysts. Accelerated degradation test (ADT) indicated that electrochemical stability of Pt/SnO2/C was twice as high as that of conventional Pt/C catalysts. The improved performance can be attributed to the presence of Pt/SnO2/C triple junction nanostructures, in which Pt nanoparticles were thermodynamically favored to deposit at the SnO2/C junctions, and then be anchored simultaneously by both SnO2 and C.

Pt/SnO2/C catalysts formed unique triple junction nanostructures, which exhibited 130% higher specific activity for ORR and 100% higher electrochemical stability than conventional Pt/C catalysts.Figure optionsDownload as PowerPoint slide