EXAFS peaks and TPR characterizing bimetallic interactions: Effects of impregnation methods on the structure of Pt-Ru/C catalysts

To investigate bimetallic interactions,pt-ru/c catalysts were prepared by coimpregnation (pt-ruco/c) and successive impregnation (ru-ptse/c),while pt/c,ru/c,and reduced pt-rublack were used as reference. those samples were characterized by xas and tpr. when pt(absorber)-ru(backscatter) phase-and-amplitude correction is applied to fourier transformed (ft) exafs of pt-rublack at pt edge,the characteristic peak of pt-ru interactions appears at 2.70 ǻ,whereas,when pt-pt correction is applied,the peak appears at about 2.5 ǻ. detailed exafs analysis for pt-ruco/c and pt-ruse/c confirms the nature of the characteristic peak and further indicates that the interactions can semiquantitatively be determined by the relative intensity between pt-ru and pt-pt characteristic peaks. this simple method in determining bimetallic interaction can be extended to characterize pt-pd/γ-al2o3. however,for pt-re/γ-al 2o3,pt-re interactions cannot be determined by the method because of the overlap of pt-pt and pt-re characteristic peaks due to similar phase functions. © 2014 nan-yu chen et al.