Structural transformations of CuMoO4 in the catalytic oxidation of carbon

Abstract

The catalytic combustion of carbon black at 350–420°C in the presence of CuMoO4 has been investigated. The separate catalyst reduction and reoxidation stages make nonadditive contributions to the overall heat of the process. This indicates the formation of catalytically intermediate compounds during the redox reactions. The reduction of the catalyst with carbon yields the copper(I) molybdates Cu6Mo5O18 and Cu4Mo5O17 on its surface. The reoxidation of the reduced phases is accompanied by the release of Cu2O and MoO3 followed by the formation of the active phase Cu4 − x Mo3O12, which is capable of activating carbon black combustion.