Highly effective CuO/Fe(OH)x catalysts for selective oxidation of CO in H2-rich stream

Ferric hydroxide supported copper oxide (CuO/Fe(OH)x) catalysts were prepared with a simple co-precipitation method and used for selective oxidation of CO in H2-rich gas. The effect of calcination temperatures and Cu loadings on the activity as well as the durability of the catalyst was investigated. When the calcination temperature was 200 °C and the Cu loading was ranging from 7.2 to 17.3 wt%, the catalyst gave the best performance with total conversion of CO achievable in a wide temperature window from 110 °C to 150 °C. To reveal the reason for the high activity of the catalysts, a variety of characterization techniques were employed. The results of XRD and TG–DTA indicated that the catalysts were amorphous even after being calcined at 400 °C, which gave rise to large surface areas. HRTEM and XPS examinations indicated that the surface copper species were Cu2O with particle size of smaller than 5 nm. In situ DRIFT and FT-IR results showed that the reduction of Cu2+ in the composite occurred even below room temperature when exposed to CO. The significant reducibility might contribute to the high activity of the catalysts.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► CuO/Fe(OH)x catalyst was prepared with a simple co-precipitation method. ► It is highly active and selective for PROX reaction with a wide temperature window. ► It shows good activity and stability even with the presence of CO2 and H2O. ► The significant reducibility might contribute to the high activity of the catalyst.