Magnetic field acceleration of the ortho-para H-2 conversion on transitionoxides

A new electron-nucleus resonant mechanism is shown to increase the ortho-pa ra conversion rate of hydrogen molecules adsorbed on transition metal oxide s. This mechanism is suggested to interpret the observed conversion rate ac celerations by an external magnetic field and similar effects in a variety of chemical reactions. Since the resonances occur for stringent relations b etween catalyst and molecular parameters, the magnetic field acceleration i s very sensitive to catalyst pretreatments and constitutes a valuable tool to improve the catalytic rates.