Co-nanocasting synthesis of mesoporous Cu-Mn composite oxides and their promoted catalytic activities for gaseous benzene removal

Abstract

Mesoporous Cu-Mn oxides with high surface area (~221m2g-1) were successfully obtained through a simple co-nanocasting approach using siliceous SBA-15 mesoporous material as a hard template. Their catalytic performances for deep oxidation of benzene were tested and physicochemical properties were characterized in detail by means of N2-physisorption, XRD, XPS, H2-TPR, SEM-EDX and TEM. The as-prepared mesoporous Cu-Mn oxides display superior catalytic activity and the temperature required for achieving a benzene conversion of 90% has been obtained at about 234°C over sample Cu0.6Mn, which is 131°C lower than that on the Cu-Mn oxide prepared by co-precipitation method using NaOH. The apparent activation energy over nanocasted catalyst was low to 45.0kJmol-1. Nanocasting process provides a limited nanoreactor for the formation of Cu-Mn composite oxide which makes the Cu-Mn oxides owing small particle size, high surface area, rich surface adsorbed oxygen species, low temperature reducibility and promoting interaction of Cu-Mn species. These characters generated by nanocasting method are responsible for its better catalytic activity. © 2014 Elsevier B.V.