Mining wastes as CO oxidation catalysts from the Fe-skarns of Serifos Island, Cyclades, Greece

Abstract

Abstract The Fe-skarns from the Greek Island of Serifos in Cyclades is utilized only for the exploitation of magnetite ores while a significantly vast amount of red and yellow hematite ores remained unexploited as mining wastes. The main aim of this study is the effective utilization of such mining wastes, as active catalytic materials for various environmental and energy applications, taking CO oxidation as a model reaction. The results from the characterization techniques have illustrated that the physicochemical characteristics of the hematite materials can positively be influenced by the implementation of a simple calcination step, while the characteristics of magnetite remained unaffected. The catalytic studies for CO oxidation reaction have shown that the increased surface area and concentration of oxygen vacancies of the calcined (yellow and red) mineral hematite from Serifos Fe-skarns mining wastes, act beneficial in the catalytic activity with respect to calcined magnetite catalyst. Moreover, the hematite materials can be utilized as suitable supports for Au/Fe2O3 catalysts, illustrating the dual role of natural hematites in catalytic applications.