Modification of composite catalytic material CumVnOx@CeO(2)core-shell nanorods with tungsten for NH3-SCR

摘要

Novel composite material CumVnOx-NF@Ce-MOF nanorods with a core-shell structure were successfully fabricated by thein situgrowth of Ce-MOF on electrospun copper vanadate precursor nanofibers. Following calcination at 500, 600 and 700 degrees C, Cu2V2O7@CeO2, Cu-3(VO4)(2)@CeO(2)and Cu11O2(VO4)(6)@CeO2, respectively, were obtained. The CeO(2)shell not only protected the copper vanadate nanofibers from breaking apart during the calcination process, but also induced an interaction between Ce, Cu and V species, which resulted in an excellent redox capacity. This revealed its potential as a catalyst for the selective catalytic reduction of nitrogen oxides with NH3(NH3-SCR). Further surface modulation was accomplished by WO(x)anchoring on the shell of CumVnOx@CeO2. According to a series of characterizations, the crystallinity of surface ceria on CumVnOy@CeO2-WO(x)was apparently reduced and the amount of acid on its surface was also significantly increased. In addition, different calcination temperatures also had nonnegligible effects on the amount of surface acid as well as the redox capacity of the composite catalytic material CumVnOy@CeO2-WOx. With the largest total quantity of acid sites as well as a suitable balance between acidity and reducing ability, the Cu-3(VO4)(2)@CeO2-WO(x)calcined at 600 degrees C exhibited satisfactory catalytic performance in the NH3-SCR process, and the NO conversion could remain above 90% at 230-380 degrees C.