## 2 Results and Discussion
### Catalytic Runs: Fresh Catalysts
Pd/mS-pSDVB10 was very little active: this shows how important is the morphology of ion-exchanger resins when they are used as catalysts or catalytic supports. In this case, it is well known that in macroreticular resins there is a more or less thick gel-phase beneath the surface of the permanent pores [27; 45]: as a rule of thumb the higher the cross-linking degree the thinner is the layer (and smaller its proportion in the polymeric material) [45]. The sulfonic groups in the gel phase can be made accessible only upon swelling, which is relatively very effective in water in view of the hydrophilic nature of the -SO\({}_{3}\)H groups. As the consequence if the ion-exchange process is carried out in aqueous environment, a part of the ions exchanged for H\({}^{+}\) (or Na\({}^{+}\) in this work) are taken up in the gel-phase. In Pd/mS-pSDVB10 this likely occurred to the [Pd(NH\({}_{3}\))\({}_{4}\)]\({}^{2+}\) ions during the preparation of the catalyst, so that they could have been excluded to some extent from the contact with H\({}_{2}\) during the reduction step in THF. In addition, the palladium nanoparticles formed in the gel phase, if any, could be excluded from the contact with the reagents of the DS due to less effective swelling in CH\({}_{3}\)OH in comparison with water. Figure 4: \(Cont.\)  
If the initial delay is neglected, all the curves in the top part of Figure 4 are practically always linear up to 4 h and those of the bottom part as well up to 80 min. This allowed to readily obtain their initials slopes, \(-\left(\frac{\partial n_{H_{2}}}{\partial t}\right)_{800}\) and \(-\left(\frac{\partial n_{H_{2}}\mathrm{O_{2}}}{\partial t}\right)_{800}\), also used to calculate the initial specific apparent rates of H\({}_{2}\) consumption (\(R_{s,H_{2}}^{80}\)) and H\({}_{2}\)O\({}_{2}\) formation (\(R_{s,H_{2}\mathrm{O_{2}}}^{80}\)) (Table 3). \begin{table}
\begin{tabular}{c c c c c} \hline  & & **Pd/\(\mu\)S-pDVB10** & **Pd/\(\mu\)S-pDVB35** & **Pd/mS-pSDVB10** & **Pd/C** \\ \hline
1 & H\({}_{2}\) feed rate (\(\mu\)mol h\({}^{-1}\)) a  & & 2452 & \\ \hline
2 & n\({}_{\mathrm{Pd}}\) (\(\mu\)mol) & 9.92 & 34.34 & 9.98 & 9.44 \\ \hline
3 & \(-\left(\frac{\partial n_{H_{2}}}{\partial t}\right)_{800}\) (\(\mu\)mol h\({}^{-1}\)) b  & 792 & 1674 & 162 & 714 \\ \hline
4 & \(-\left(\frac{\partial n_{H_{2}}\mathrm{O_{2}}}{\partial t}\right)_{800}\) (\(\mu\)mol h\({}^{-1}\)) c [FOOTNOTE:c]Footnote c: \(\mathrm{a}\) 9.8 mmol of H\({}_{2}\) are fed per step run overall; b initial slopes of curves up to 80 min in Figure 4 measured from the end of delay and induction time; c total amount of H\({}_{2}\) consumed in the run (\(\Delta nH_{2}\)) over the total reaction time (\(\Delta t\)); d initial slopes of curves in Figure 5 measured from the end of delay and induction time up to 80 min; e total amount of H\({}_{2}\)O\({}_{2}\) formed in the run (\(\Delta nH_{2}\)) over the total reaction time (\(\Delta t\)); d calculated as the ratio of entry 3 over entry 2 in the same column; b calculated as the ratio of entry 4 over entry 2 in the same column; b calculated as the ratio of entry 5 over entry 2 in the same column; c calculated as the ratio of entry 3 over entry 1 in the same column; c calculated as the ratio of entry 3 over entry 1 in the same column; c calculated as the ratio of entry 5 over The final rate values \((\left(\frac{\Delta n_{H_{2}}}{\Delta t}\right)_{240t}\left(\frac{\Delta n_{H_{2} \mathrm{O_{2}}}}{\Delta t}\right)_{240t}\), \(R_{s,H_{2}}^{240t}\), \(R_{s,H_{2}}^{240t}\), Table 3) were simply obtained from the ratios between the number of moles of H\({}_{2}\) consumed and H\({}_{2}\)O\({}_{2}\) formed at the end of the reaction, respectively, and the reaction time (4 h). The values of \(\Delta t\) employed for this calculation included also the initial delay and/or induction times, but they were apparently short enough to have a negligible effect on the results.