## 3 Results and Discussion  
Inspired by our previous work on the hydrogenation of LA using Cu-containing silica materials, we designed a supported iron oxide catalyst on porous silicates based on our previous report [30,33]. We applied a simple, innovative, and efficient continuous flow methodology for the deposition of iron oxide nanoparticles on porous materials. Textural properties of synthesized materials in this work are summarized in Table 1. All final materials exhibited high surface areas (>600 m\({}^{2}\)g\({}^{-1}\)), in good agreement with typical characteristics of mesoporous SBA-15 materials. The incorporation of Fe in the systems did not have any significant effect on the textural properties of supported materials in terms of surface area, pore size and volume, in good agreement with previously observed surface deposition of Fe species under continuous flow preparation [33]. Fe loading was found to be less than 1 wt%, with a slightly higher loading observed for FeAlCF with respect to FeZrCF. No significant differences were obtained between ICP and EDX analysis, which correlated well with previous synthesized catalytic nanomaterials under flow conditions [33]. Both Pd systems (PdAlCF and PdASBA-BM) contained _ca_. 0.5-0.6 wt% Pd as measured by ICP/MS (results not shown), an almost comparable metal loading to that of analogous Fe-containing aluminosilicates from this work regardless of the synthesis protocol. Similarly to previously reported work [33], Fe species in the materials were found to correlate to a hematite Fe\({}_{2}\)O\({}_{3}\) phase with nanoparticle sizes in the 5-7 nm range (clearly visualizable in the TEM micrographs around the edges, Figure 2). \begin{table}
\begin{tabular}{c c c c c c c} \hline \multirow{2}{*}{**Material**} & **Surface area 1 ** & **Pore volume 2 ** & **Elemental composition 3 ** (\%)** \\  & **(m\({}^{2}\)g\({}^{-1}\))** & **(nm)** & **(mLg\({}^{-1}\))** & **Fe 4 ** & **Al** & **Zr** \\ \hline Al-SBA-15 & 720 & 8.5 & 0.80 & - & 2.0 & - \\ Zr-SBA-15 & 765 & 7.4 & 0.74 & - & - & 4.0 \\ FeAlCF & 659 & 8.2 & 0.77 & 0.85 & 1.1 & - \\  & & & (0.6) & & \\ FeZrCF & 687 & 7.0 & 0.66 & 0.53 & - & 3.9 \\  & & & & (0.7) & & \\ PdAlCF & 633 & 7.9 & 0.70 & - & 1.2 & - \\ PdAlSBA-BM & 507 & 8.5 & 0.92 & - & 1.1 & - \\
5\%Pd/C & 1220 & \textless{}2 & 1.50 & - & - & - \\ \hline \end{tabular}
\end{table} 
Table 1: Textural properties and ICP-MS analysis of mesoporous silicates synthesized in this work. Catalytic activities of the investigated catalysts in the hydrogenation of LA have been summarized in Table 2. Reactions were carried out under microwave irradiation (MI) for a quick screening and optimization of reaction conditions. FA served as both solvent and hydrogenating agent which efficiently decomposed under microwave mild heating to provide the needed _in situ_ generated hydrogen for the hydrogenation reaction based on previous work by the group on FA-assisted lignin depolymerization [34,35]. The present reaction conditions provided very low LA conversion (\(<\)5%) in the absence of catalyst (blank run) and in the presence of the parent Al- and Zr-SBA-15 supports even at 200 \({}^{\circ}\)C (Table 2). Gratifyingly, the incorporation of Fe\({}_{2}\)O\({}_{3}\) nanoparticles even at low loading (\(<\)1 wt%) in newly explored iron-based catalysts provided moderate LA conversion under the investigated reaction conditions (Table 2, entries 4 and 5). Typical LA conversions in the systems were ca. 30% with a _ca._ 45% increase pushing reaction conditions (200 \({}^{\circ}\)C, 60 min, 100 mg FeZrCF catalyst). TON values obtained for most active catalysts FeZrCF (62) and FeAlCF (26) and particularly TOF values (Table 2) pointed to a