Optimized CuO–CeO2 catalysts for COPROX reaction

CuO–CeO2CuO–CeO2 catalyst precursors were synthesized by homogeneous thermal decomposition of urea. Catalysts containing different Cu/Ce ratios were obtained after calcination of the precursors at 450∘C and characterized by ICP-OES, N2N2 adsorption, XRD and TPR. Catalytic tests were performed in the temperature range 100–300∘C to evaluate the activity of these samples for the COPROX reaction. A strong synergy between Cu and Ce is evidenced by the difference in the catalytic activity of the individual oxides (CuO and CeO2CeO2), a mechanical mixture of both oxides and a Cu–Ce mixed catalyst. The synergy between Cu and Ce is confirmed by the improvement of the reducibility of both cations in the mixed samples. Nitric acid and ammonium carbonate washed catalysts, especially high-copper-content samples, are more active than the untreated catalysts suggesting that the washing procedure could provoke a destruction of the polycrystalline structure that improves the contact between the reactants and the catalytic sites.