Catalysis by “Copper Chromite”. I. The Effect of Hydrogen Reduction on the Composition, Structure, and Catalytic Activity for Methanol Decomposition

The effect of hydrogen reduction on the composition, structure, and catalytic activity of dichromium(III) copper(II) tetraoxide (copper chromite), CuCr2O4, was investigated. In this oxide, the surface and the bulk CuII was reduced into CuI and further to Cu0 by heating in hydrogen. The methanol decomposition on fresh copper chromite proceeded in a manner similar to that on metallic copper formed as the result of strong reduction and dispersed on chromium(III) oxide. The contribution of CuII, CuI, and Cu0 species to catalytic activity was examined and the similarity in the character of reaction on these two samples with different surface states was discussed. The role of Cr2O3 interacting with zerovalent copper was postulated.