## 4 HPS-Based Catalysts for the Synthesis and Transformation of Platform Chemicals
### Magnetic Catalysts Based on HPS in the Conversion of Plant Polysaccharides
The results obtained are shown in Table 4.  
It was found that the glycol selectivity with the 3% Ru-Fe\({}_{3}\)O\({}_{4}\)/MN270 magnetic catalyst is approximately equal to the selectivity of 5% Ru-Fe\({}_{3}\)O\({}_{4}\)-SiO\({}_{2}\) at the same conversion level [149]. However, due to the lower ruthenium content of the HPS catalyst, its specific activity (calculated per gram of Ru) was higher by 35% for EG and 20% for PG. A comparison of the results for the 3% Ru/MN270 (Table 5, entry 3) and for the 3% Ru-Fe\({}_{3}\)O\({}_{4}\)/MN270 catalysts shows that Fe\({}_{3}\)O\({}_{4}\) promotes hydrogenolysis, increasing the yield of glycols. According to [151; 152], the activity and selectivity of catalytic hydrogenation are significantly improved when catalytic nanoparticles are supported on iron oxide. Moreover, an intimate contact of catalytic and magnetic nanoparticles can lead to electron transfer from the iron oxide to ruthenium surface [153], facilitating hydrogenation [154]. The reuse of the 3% Ru-Fe\({}_{3}\)O\({}_{4}\)/MN270 catalyst in multiple reaction cycles showed its stability under hydrothermal conditions without any loss of magnetic properties [143]. This is an important advantage for its application in biomass processing, which often is characterized by incomplete conversion of the initial substrates and the formation of large number of byproducts; a separation of the catalyst thus becomes a challenge. This catalyst was also used for the hydrolytic hydrogenation of inulin, a plant polyfractosan (Figure 6). The high content of inulin in some plants allow this polysaccharide to be a promising renewable source for the production of chemicals and fuel [155]. For example, Jerusalem artichoke (_Helianthus tuberosus_ L.) contains up to 82% inulin and has great  
Figure 5: XRD pattern of the Fe\({}_{3}\)O\({}_{4}\)/MN270 [145]. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Catalyst**} & \multirow{2}{*}{\
\begin{tabular}{c} **Cellulose** \\ **Conversion, \%** \\ \end{tabular} } & \multirow{2}{*}{
\begin{tabular}{c} **Selectivity, \%** \\ **Cram of EG (or PG) g\({}^{-1}\) Ru h\({}^{-1}\)** \\ \end{tabular} } \\ \cline{3-6}  & & **EG** & **PG** & **EG** & **PG** \\ \hline
3\% Ru-Fe\({}_{3}\)O\({}_{4}\)/MN270 & 100 & 22.6 & 20.0 & 39.12 & 34.62 \\
5\% Ru-Fe\({}_{3}\)O\({}_{4}\)-SiO\({}_{2}\) & 100 & 19.1 & 20.9 & 25.29 & 27.72 \\
3\% Ru/MN270 & 95 & 7.2 & 12.3 & 7.51 & 12.71 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Catalytic activity/selectivity in the hydrogenolysis of microcrystalline cellulose. prospects for cultivation. The main product of the reaction is mannitol, which is used, in particular, in the treatment of brain diseases [156], as a food additive, in perfumery, and for the production of varnishes, resins, surfactants, and other products [157; 158]. [PERSON] et al. [159] studied the conversion of inulin to mannitol using Ru-containing activated carbon treated with ammonium persulfate as a catalyst. The maximum selectivity for mannitol was 40%. The authors found a certain amount of short-chain inulin oligomers of the GF\({}_{\rm n}\) composition (G-glucose, F-fructose) in the solution. The authors explain their presence in the reaction medium after the reaction completion by the fact that the formation of hexitols from inulin occurs simultaneously along two paths: hydrolysis of inulin to monosaccharides with their subsequent hydrogenation and hydrogenation of F\({}_{\rm m}\) fragments of inulin with their subsequent hydrolysis. The GF\({}_{\rm n}\) fragments formed during the hydrolysis of inulin do not undergo hydrogenation and accumulate in some quantities in the catalyst. In [160], the process of hydrolytic hydrogenation of inulin was studied in the presence of a Ru-containing homogeneous catalyst based on trisulfonated triphenylphosphine ((TPPTS, \(P\)(\(m\)-C\({}_{6}\)H\({}_{4}\)SO\({}_{3}\)Na)\({}_{3}\))--Ru-TPPTS.