SYNTHESIS OF HIGHER ALCOHOLS ON CU-CONTAINING CATALYSTS - IN-SITU STUDY OF THE CATALYST

The phase composition of a copper-cobalt catalyst in the course of the reduction by hydrogen and in the reaction medium is examined by high- temperature bl situ X-ray diffraction analysis, ex situ transmission m icroscopy, and thermography. In the hydrogen medium at 230 degrees C, a model CuCoO2 catalyst is completely transformed into the copper-coba lt melt, which partially decomposes under the action of a CO + H-2 mix ture on heating to 280 degrees C to give cobalt carbide and Cu-0. Heat ing to 370 degrees C causes the decomposition of cobalt carbide and th e Cu-Co melt to yield cobalt and copper separate metallic phases. This is accompanied by the formation of carbon from cobalt carbide. The ph ase composition of the catalyst in the reaction medium is related to t he selectivity of CO hydrogenation. The role of carbide in the formati on of active sites in the synthesis of higher alcohols is discussed.