The interaction of hydrogen with copper-containing spinels CuFe 2 O 4 and CuFeCrO 4 , which are the catalysts for hydrogenation, alkylation and other reactions, was studied. Copper ions of ferrite are reduced in a reductive atmosphere and segregated to the spinel Fe 3 O 4 surface with the formation of Cu 0 nanoparticles; their interaction with O 2 -contaning (less than 1 vol.%) helium leads to the oxidation to Cu 2 O or CuO. In a reductive medium, copper ferrite-chromite CuFeCrO 4 segregates copper ions from spinel, which are reduced to Cu 0 nanoparticles on the surface of CuFeCr-spinel. Charge compensation of spinel structure occurs due to formation of OH groups and by the partial transition Fе 3+ – Fe 2+ . Upon mild reoxidation, Cu 0 atoms partially return into the spinel structure and partially form the Cu 2 O phase.
|Журнал||Materials Research Bulletin|
|Состояние||Опубликовано - 1 окт 2019|