Use of a dihydrogen plasma afterglow for the reduction of zeolite-supported gold-based metallic catalysts

The afterglow of a microwave plasma (2450 MHz) of dihydrogen is used for the preparation of gold-based metallic catalysts. It contains hydrogen atoms at a sufficiently low temperature for the formation of nanoparticles, whereas the reduction of gold at high temperature often leads to large particles. The study concerns the search for optimal conditions for the preparation of monometallic (Au, Pd) or bimetallic (Au/Pd) catalysts. The position of the sample in the afterglow and the exposure time are varied. According to transmission electron microscopy, the particles are less than 5 nm in size.