MECHANICALLY DRIVEN CO HYDROGENATION OVER NIZR AMORPHOUS CATALYSTS

The mechanically driven process of CO hydrogenation over NiZr amorphous powders is presented. Special milling vials were employed as reactors; the structure of the powders was checked by correlating X-ray and thermal analysis data; the gaseous products were sampled at different steps during the reaction. The sequence of structural changes accompanying CO and hydrogen activation starts with increase in the specific surface area and contact surface, and diffusion is promoted. Zr oxide species develop and crystalline Ni demixes from the destabilized matrix. After an induction step, the formation of hydrocarbons was observed with a very high selectivity to methane. This behaviour was compared with the activity and selectivity of NiZr amorphous alloys run in a conventional flow-type reactor.