Embedding platinum-based nanoparticles within ordered mesoporous carbon using supercritical carbon dioxide technique as a highly efficient oxygen reduction electrocatalyst

Abstract

Ordered mesoporous carbon (OMC) has shown great promising as superior support in the creating highly efficient and stable cathodic catalyst for oxygen reduction reaction (ORR) due to its many merits but there are still many challenges. We demonstrate in this work a facile and large-scale strategy to efficiently embed Pt-based crystals within OMC using supercritical carbon dioxide (scCO2) technique. Typically, PtFe/OMC catalysts with the highly dispersive, ultrafine sizes (1.3–2.3 nm), controllable compositions and loadings have been successfully fabricated. Through control of experimental process and loadings, most of crystals can be deposited into mesochannels of OMC. The integration of highly dispersive and ultrafine PtFe crystals as well as high surface area, mesoporous structure and good electrical conductivity of OMC supports make PtFe/OMC promising as active and stable electrocatalysts toward ORR. By careful comparison, PtFe/OMC catalysts show the overwhelmingly better or comparable electrochemical performance compared with previously reported mesoporous carbon supported Pt-based catalysts. These attractive materials hold great potential in cathodic electrocatalyst for fuel cells and the scCO2 technique is quite superior for constructing OMC with various embedded nanoparticles (such as PtPd, PtCu etc.)