Abstract
In this study, we used the mesoporous silica hollow spheres with Ia3d symmetry as template which was developed by our lab to synthesize mesoporous Platinum and Platinum-based alloy hollow spheres and apply it to oxygen reduction reaction (ORR). Traditionally, the template synthesis cannot make a complete replication of mesoporous silica. We solve the problem because our template has the property of high pore volume and hollow core and we could replicate template morphology completely by impregnating large quantity metal precursor and hydrogen reduction. In the Pt replica, we successfully synthesized by one step impregnating large quantity molted metal precursor and low temperature reduction. In the Pt-based alloy replica, we used incipient wetness impregnation to homogenize mixtures of the precursors and got alloy replica after reduction. The template and metal hollow spheres was characterized by X-ray diffraction, nitrogen physisorption, scanning electron microscopy, transmission electron microscopy and X-ray absorption spectroscopy. Finally, the replicas as catalysts were test by voltammetry. We found that the mesoporous Platinum and Platinum-based alloy hollow spheres have higher ORR catalytic activity and stability than the commercial carbon support platinum and platinum black catalysts.