Supported palladium catalysts prepared by surface self-propagating thermal synthesis

Supported Pd/fiber glass, Pd/γ-Al2O3/fiber glass, Pd/γ-Al2O3 catalysts were prepared by Surface Self-propagating Thermal Synthesis (SSTS) and tested in selective hydrogenation of acetylene to ethylene in the presence of CO. Temperature change in local liquid-phase surrounding of Pd atoms was monitored by XAFS in situ by modeling the catalysts synthesis. The phase composition of samples at various synthesis stages was determined by XAFS spectroscopy and synchrotron X-ray diffraction (SR XRD). The type of support material and SSTS conditions were found to affect the catalytic activity of supported Pd catalysts. Thermal synthesis of Pd catalysts on the surface of supports was found to proceed via formation of the metallic phase followed by its transformation to oxide. The catalytic activity of thus prepared catalysts on fiber glass supports can expectedly be improved upon deposition of additional support (alumina) onto a fiber glass.