Mechanochemical Synthesis as an Alternative Effective Technique for the Preparation of the Composite Catalysts

Abstract

—Mechanochemical synthesis in a ball mill was applied for the nanocomposite Cu(CuO)–CeO2 catalyst preparation from CeO2 and following dopants: Cu metal and copper oxides of different morphology and composition (CuO pure and CuO containing 4 or 16.5 wt % of Cu2O). The materials obtained were examined with the use of X-ray phase analysis, scanning electron microscopy, temperature-programmed reduction in CO, H2, C2H6 (TPR-СО, TPR-Н2, and TPR-С2Н6), and tested as catalysts in reactions of selective CO oxidation in H2 excess (CO-PROX) and total C2H6 oxidation. New forms of oxygen with high low-temperature reactivity towards CO, H2, and C2H6 were found by TPR in the samples synthesized. It was shown that CO conversion was slightly affected by the dopant nature in the dopant-CeO2 mixture. Contrary, C2H6 conversion at low temperatures depends on dopant composition. The highest C2H6 conversion at 400°С (91.4%) was observed on Cu–CeO2. The lowest one (54.2%) was observed on CuO–CeO2. As was demonstrated, mechanochemical synthesis is a universal technique to produce copper oxide–ceria catalysts.