Catalytic performance of manganese doped CuO-CeO2 catalysts for selective oxidation of CO in hydrogen-rich gas

摘要

Manganese doped CuO-CeO2 catalysts (CuO-MnOx-CeO2) with Mn/Cu molar ratio of 1: 5 and variable calcination temperatures were prepared by a hydrothermal method and used for selective oxidation of CO in hydrogen-rich gas, characterized by various techniques. An appropriate calcination temperature shows an essential stimulative effect on CuO-MnOx-CeO2 catalysts for the CO-PROX. The catalyst calcined at 500 degrees C displays the highest low-temperature catalytic activity (T-50% = 74 degrees C) and the broadest operating temperature "window" (CO conversion > 99.0%, 110-140 degrees C). XRD and UV-Raman results reveal that an appropriate calcination temperature can promote the formation of Cu-Mn-Ce-O ternary oxide solid solution, adjust the degree of crystallinity of CeO2 and enhance the formation of oxygen vacancies. H-2-TPR and XPS demonstrate that calcining at 500 degrees C improves the active reducing species in both bulk and surface of the catalyst. In situ DRIFTS suggests that Cu+ species which possess strong interaction with ceria also can be facilitated with a suitable calcination temperature. (C) 2015 Elsevier Ltd. All rights reserved.