## 2 Results
HPS-based Pd-containing catalysts were tested in the reaction of the selective hydrogenation of MBY in a batch mode at 90 \({}^{\circ}\)C, with toluene as a solvent. It was found that Pd/OF2 and Pd/OF3 have the highest activity (Figure 5a), while the selectivity for all samples was similar (96-97% at 95% of MBY conversion, see Figure 5b and Table 1, #1-4). Figure 4: Normalized _DRIFT_ spectra of synthesized polymers. Figure 3: Comparison of pore-volume distributions of synthesized HPS samples (a) and Pd/HPS catalysts (b). The difference in the observed activity has no dependence on the samples' porosity and can be due to the different distribution and sizes of Pd NPs. It is noteworthy that all the initial samples were unreduced and contained Pd(II). As it was supposed in one of our previous publications [27] and also shown in the work of [PERSON] et al. [28], formation of Pd NPs occurs effectively in situ in the presence of the substrate. A slight induction period, which can be seen on the presented kinetic curves (Figure 5a), confirms that preliminary treatment of the catalysts with molecular hydrogen in a liquid phase (toluene) at 90 \({}^{\circ}\)C, ambient pressure did not allow for complete Pd reduction, and the formation of active centers continued in situ under reaction conditions. After the MBY hydrogenation, the catalysts were separated by vacuum filtration, thoroughly washed with toluene and chloroform, dried at 65 \({}^{\circ}\)C overnight, and the Pd NPs' sizes were analyzed by scanning/transmission electron microscopy (S/TEM) (Figure 6). It was found that among these four samples, Pd NPs were more evenly distributed in Pd/OF2 (Figure 6e,f) and Pd/C7 (Figure 6a,b), which were synthesized using micro-mesoporous polymers. NPs with the lowest mean diameter, of 1.5 \(\pm\) 0.5 nm, and an absence of aggregates were found in Pd/OF2 (Figure 6e,f), where only a few particles with a diameter about 10 nm were observed. In the case of Pd/C7, the mean diameter of Pd NPs was 5.9 \(\pm\) 2.0 nm (Figure 6a). Moreover, these NPs formed aggregates up to 30 nm in diameter (Figure 6b), likely due to their migration after nucleation under reaction conditions. For other two samples, the mean diameters of Pd NPs were 7.4 \(\pm\) 2.6 nm (Pd/PS, Figure 6c) and 7.8 \(\pm\) 3.9 nm (Pd/OF3, Figure 6d). Moreover, a number of dense \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**N** & **Catalyst** & **Substrate** & **Product** & **S\({}_{95}\)\(\pm\) 0.5, \% 2** & **X\({}_{\text{max}}\) (S) \(\pm\) 0.5, \% 1** & **R\({}_{0}\)\(\pm\) 0.1, mol\({}_{\text{sub}}\)/(mol\({}_{\text{Pd}}\)*s) 3** \\ \hline
1 & Pd/C7 & & & 96.0 & 99.9 (95.1) & 10.2 \\
2 & Pd/PS & & 96.5 & 99.0 (96.3) & 4.6 \\
3 & Pd/OF2 & & 97.2 & 99.6 (94.7) & 25.4 \\
4 & Pd/OF3 & & & 95.1 & 99.9 (94.2) & 17.2 \\ \hline
5 & Pd/OF2 & & 95.6 & 98.5 (95.5) & 61.8 \\
6 & Pd/OF3 & & 94.2 & 97.1 (94.0) & 16.8 \\ \hline
7 & Pd/OF2 & & - & 90.3 (92.9) & 48.4 \\
8 & Pd/OF3 & DHIP & IP & 92.5 & 100 (90.5) & 30.4 \\ \hline \end{tabular}  
* \({}^{1}\) X\({}_{\text{max}}\)—maximum conversion observed in one experiment; 2 S\({}_{65}\)—selectivity calculated at X = 95\(\%\)3 \({}^{3}\)_R\({}_{0}\)—_initial transformation rate.  
\end{table} 
Table 1: Data of HPS-based catalysts, testing in hydrogenation ofalkynols (solvent—toluene, temperature 90 \({}^{\circ}\)C, ambient hydrogen pressure). Figure 5: Kinetic curves of 2-methyl-3-buten-2-ol (MBE) accumulation (**a**) and dependence of the selectivity with respect to MBE on MBY conversion of (**b**). aggregates with diameters up to 42 nm were found, especially in the case of Pd/OF3. The formation of larger Pd NPs and their aggregates cannot be explained by the about 1.5-fold higher Pd amount for these two samples (Pd/PS and Pd/OF3), in comparison with the other ones (Pd/C7 and Pd/OF2).