Page 225 - Advances in bioenergy (2016)

catalyst exhibiting higher selectivities toward H and CO and lower selectivity toward CO
2
2
because of the enhancement of the WGS reaction. The improved catalytic performance of
Pt/CeO catalysts has been related to the greater ability of CeO to release and store oxygen,
2
2
resulting in higher stability compared with Pt/Al O catalysts. 36
2 3
Recent studies over supported Pt catalysts showed that the conversion of ethanol is higher
when Pt is dispersed on ZrO , compared with CeO , whereas Al O -supported catalyst
2
2
2 3
37
exhibits intermediate performance (Figure 9.3a). The main difference observed between the
investigated supports is related to variations of CO and CO selectivities. As it can be seen in
2
Figure 9.3(b), selectivity to CO is significantly affected by the nature of the support and is
lower over Pt supported on ZrO and CeO , which enhance the WGS reaction.
2 2

Figure 9.3 (a) Effect of the nature of the support on the catalytic performance and (b)
selectivity toward CO over Pt (0.5 wt%) supported on the indicated commercial oxide
37
carriers. Experimental conditions: same as in Figure 9.2. (Reproduced in part from Ref .
Copyright 2012, Elsevier.)