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 coprecipitation method and used for selective oxidation of CO in H-2-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 degrees 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 degrees C to 150 degrees 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 degrees 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. (C) 2011 Elsevier B.V. All rights reserved.