Interparticle readsorption

Figure 3 shows three TPD spectra ranging from 0.1 to 0.3 g of catalyst sample. Besides the amount of CO desorbed, no major change in the spectra was observed. However, a small discernible shift to increasing temperatures is seen on increasing sample amount which suggests a small interparticle readsorption effect. 

Fig. 7. Experimental determination of the mean surface-residence time in the presence of interparticle readsorption.

Interpretation of pubhshed data is often comphcated by the fact that rather complex catalytic materials are utilized, namely, poly disperse nonuniform metal particles, highly porous supports, etc., where various secondary effects may influence or even submerge PSEs. These include mass transport and discrete particle distribution effects in porous layers, as confirmed by Gloaguen, Antoine, and co-workers [Gloaguen et al., 1994, 1998 Antoine et al., 1998], and diffusion-readsorption effects, as shown by Jusys and co-workers for the MOR and by Chen and Kucemak for the ORR [Jusys et al., 2003 Chen and Kucemak, 2004a, b]. Novel approaches to the design of ordered nanoparticle arrays where nanoparticle size and interparticle distances can be varied independently are expected to shed hght on PSEs in complex multistep multielectron processes such as the MOR and the ORR. 

---