Hydrogen reactivity toward carbon monoxide under mechanochemical processing

The study focuses on the hydrogenation of carbon monoxide over Co–Fe-based catalysts.
The catalytic reactions were performed under both isothermal and mechanical activation
conditions and their rates estimated by monitoring the gradual consumption of carbon
monoxide. Aimed at carrying out a sound comparison, the rate of mechanically activated
processes was referred to individual collisions by normalizing its value to the amount of
powder involved in individual collisions and to the time interval of ongoing deformation.
This allowed to point out that the amount of carbon monoxide converted per unit of
catalyst mass and unit of time under mechanical activation conditions is at least four
orders of magnitude larger than the one reacted under thermal activation conditions. This
result is tentatively connected with the generation of local excited states at the catalyst
surface.