Reactivity of nanocrystalline copper oxide and its modification under magnetic field

The influence of magnetic field on the rate of oxidative dehydrogenation of 2,3,5-trimetyl-1,4-hydroquinone (TMHQ) to 2,3,5-trimetyl-1,4-benzoquinone (TMBQ) with catalysts based on copper oxide nanopowders has been investigated. The initial transformation rate of TMHQ and the final product yield greatly increase after a preliminary magnetization of nanopowders. The adsorption ability of Cu-oxide-based nanopowders with respect to ammonia enhances by 1.5 after their magnetization. Physical mechanism of reactivity variation of CuO nanopowders under the influence of weak stationary external magnetic field (H≤3 kOe) has been proposed. As a result of magnetic field influence, the ferromagnetic regions with modified spin and charge state have appeared in an antiferromagnetic CuO of nonstoichiometric composition. These regions can be new catalytic or adsorption centers.