## Materials and Methods
### Characterization  
Thermogravity analysis (TG/DTG) experiments were performed at a heating rate of 10 \({}^{\circ}\)C min\({}^{-1}\) up to 1000 \({}^{\circ}\)C with a N\({}_{2}\) flow of 8.0 mL-min\({}^{-1}\) (209F1 Iris, NETZSCH TG, Selb, Germany), using a sample mass of 3.0 mg. The nitrogen adsorption isotherms were measured using a Micromeritics equipment model TriStar II Series 2 instrument (Norcross, GA, USA) at -196 \({}^{\circ}\)C on samples previously treated by degasification for 3 h at 120 \({}^{\circ}\)C. The specific surface areas and pore size distributions were calculated using the Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BIH) methods, respectively. The catalyst morphologies were determined by scanning electron microscopy (SEM, Vega 3 LMU, TESCAN, Brno, Czech Republic) coupled with energy-dispersive X-ray spectroscopy (EDS). NMR spectroscopy (\({}^{13}\)C decoupled, \({}^{1}\)H, C-H correlation, and solid-state cross polarized magic angle spinning (CP/MAS)) was carried out on a Bruker ASCEND 400 MHz spectrometer (Billerica, MA, USA) with an inverse multinuclear probe. The diffuse reflectance spectroscopy (DRS) UV-vis measurements  
\begin{table}
\begin{tabular}{l c c c c c c c} \hline \hline
**Label** & & & **wt.\%** & & **Grain Diameter \({}^{1}\)\(\mu\)m** & **S\({}_{\text{BET}}\)** & **Pore Size** \\  & **DVB** & **MA** & **AIBN** & **PdAS** & & **m\({}^{2}\)g-1** & **nm** \\ \hline PdAS(1)-MA & 60 & 38 & 1 & 1 & 184 \(\pm\) 20 & 586 & 17.0 \\ PdAS(2)-MA & 60 & 37 & 1 & 2 & 196 \(\pm\) 28 & 665 & 19.7 \\ PdAS(5)-MA & 60 & 34 & 1 & 5 & 227 \(\pm\) 32 & 671 & 17.3 \\ PdAS(10)-MA & 60 & 29 & 1 & 10 & 272 \(\pm\) 41 & 754 & 22.3 \\ \hline \hline \end{tabular}  
\({}^{1}\) Based on the average pore diameter from Gaussian diameter distribution.  
\end{table}
Table 1: Nominal composition of divinylbenzene (DVB), methyl acrylate (MA), 2,2’-azobis(2-methylpropionitrile) (AIBN) and N,N’-bis(3-ally-salicylidene)o-phenylenediamine palladium(II) (PdAS), scanning electron microscopy (SEM) grain diameter, surface area and pore size for PdAS(x)-MA polymers.  
were carried out on a Thermo Scientific Evolution 260 Bio UV-vis spectrophotometer (Waltham, MA, USA). Liquid phase UV-vis spectra were recorded on a Spectroquant Pharo 300 instrument (Thomas Scientific, Swedesboro, NJ, USA), using DCM as the solvent. Palladium quantification was carried out by inductively coupled plasma optical emission spectrometry (ICP-OES) using a Spectro Arcos instrument (Kleve, Germany). Samples were previously digested in a mixture of concentrated HNO\({}_{3}\) and H\({}_{2}\)SO\({}_{4}\) under microwave irradiation using a Milestone Srl Ethos Easy (Brendby Kommune, Denmark) apparatus prior to dilution for analysis. Pd quantification of the post-reaction liquid phase was measured by Atomic Absorption Spectroscopy (AAS) using a Thermo Scientific iCE 3000 Series AA-spectrometer (Waltham, MA, USA). XPS measurements were performed using a Surface Analysis Station 1 electron spectrometer (XPS RQ300/2, Staib Instrumente GmbH, Langenbach, Germany) equipped with a hemispherical electron analyzer DESA 150 detector/2700V and non-monochromatic Al K\(\alpha\) (1486.6 eV) X-ray source.