Abstract
A series of novel nanocomposites constituted of FeCo nanoparticles dispersed in an ordered cubic Im3m mesoporous silica matrix (SBA-16) have been successfully synthesized using the wet impregnation method. SBA-16, prepared using the non-ionic Pluronic 127 triblock copolymer as a structure-directing agent, is an excellent support for catalytic nanoparticles because of its peculiar three-dimensional cage-like structure, high surface area, thick walls, and high thermal stability. Low-angle X-ray diffraction, N(2) physisorption, and transmission electron microscopy analyses show that after metal loading, calcination at 500 A degrees C, and reduction in H(2) flux at 800 A degrees C, the nanocomposites retain the well-ordered structure of the matrix with cubic symmetry of pores. FeCo alloy nanoparticles with spherical shape and narrow size distribution (4-8 nm) are homogeneoulsy distributed throughout the matrix and they seem in a large extent to be allocated inside the pores.