Fabrication of macroporous platinum using monodisperse silica nanoparticle template and its application in methanol catalytic oxidation

This is to report a practical and convenient method for 3D macroporous Pt synthesis based on the monodispersion silica template. The silica nanospheres were fabricated using an improved Stöber method. The alternative method of tetraethoxysilane (TEOS) addition to the reaction system was found to be helpful in gaining silica spheres with high monodispersion. The diameter of the final silica spheres increased proportionally with adding TEOS. The silica template was built with the self-assembling method by dispersing a dilute suspension of SiO2 nanosphere onto the smooth Au support surface. After evaporating the solvent naturally, a three-dimensional template with some void spaces around the arranged nanospheres, on the Au slide, was obtained. The macroporous Pt was synthesized by electrodeposition of Pt into the void spaces of the template, which was confirmed by SEM images. The surface activities of the resultant macroporous Pt were investigated by comparing the hydrogen adsorption/desorption peaks in H2SO4 and the methanol oxidation activity. The resultant macroporous Pt displayed high activity level during Pt loading of 0.532 mg cm−2. The current work presents a useful method for nanoparticle synthesis, 3D template and macroporous material fabrication.