Fabrication of platinum coating on continuous porous SiC–Si3N4 composites by the electroless deposition process

Continuous porous SiC–Si3N4 composite fabricated by a multi-pass extrusion process was investigated using SEM, XRD and TEM techniques. In the continuous pore regions, many single crystalline Si3N4 whiskers with an average diameter of about 1 μm, which could increase the surface area of the porous composites, were observed. However, to make a platinum coating on the composite, the electroless deposition method was adapted. The spot-type platinum particles, with a diameter of about 50–500 nm, attached to the SiC–Si3N4 matrix as well as the surface of the Si3N4 whiskers, which can enhance the catalytic activity.