## 2 Results and Discussion
### Ethylbenzene Oxidation
However, the addition of [emim][OcOSO\({}_{3}\)] caused a slight decrease in selectivity toward ethylbenzene hydroperoxide (from 29.0% to 19.1%) and an increase in selectivity toward acetophenone (from 12.7% to 20.4%). Based on Figure 4, the oxidation reactions performed by the PS-NHPI-4 and PS-NHPI-4@[emim][OcOSO\({}_{3}\)] systems followed very similar trajectories. A different relationship was observed in our previous work [41], which discussed ethylbenzene oxidation by a system containing a heterogeneous NHPI catalyst immobilized on silica gel (SiOCONHPI; Figure 1c). Specifically, covering the SiOCONHPI catalyst with the ionic liquid, [bmim][OcOSO\({}_{3}\)], caused a decrease in the conversion of ethylbenzene, from 8.6 to 6.1%. The results demonstrate that coating PS-NHPI-4 with a layer of [emim][OcOSO\({}_{3}\)] containing CoCl\({}_{2}\) leads to increase ethylbenzene conversion (Table 3, entries 2,3,13). However, the conversion and TON decrease, as compared to the conversion observed for the analogous PS-NHPI-4/CoCl\({}_{2}\) system (Table 3, entries 8,13). For the PS-NHPI-2, PS-NHPI-3, and PS-NHPI-5 catalysts (Table 3, entries 6, 7, 9 and 11, 12, 14), the presence of an ionic liquid caused a decrease in selectivity toward ethylbenzene hydroperoxide. For PS-NHPI-2, PS-NHPI-3, PS-NHPI-4, and PS-NHPI-5 (Table 3, entries 6-9 and 11-14), addition of the ionic liquid led to increased selectivity toward production of acetophenone. Figure 4: The reaction evolution of ethylbenzene oxidation with dioxygen in the presence of PS-NHPI-4 and PS-NHPI-4@[emim][OcOSO\({}_{3}\)]. A particularly significant increase in selectivity toward ketone production was observed as a result of ionic liquid addition in the systems containing PS-NHPI-3, PS-NHPI-4, and PS-NHPI-5 catalysts (Table 3, entries 7-9 and 12-14). These catalysts are characterized by essentially regular grain sizes even after NHPI binding (Figures S8-S10). The relatively lower selectivities toward hydroperoxide production, in favor of ketone production, obtained for these SCILL/SILP systems may result from the higher CoCl\({}_{2}\) concentration in the IL layer, which promotes better contact between the co-catalyst and the EBOOH oxidation product. Selectivities comparable to those reported here for acetophenone production (~70%) were reported for the oxidation of ethylbenzene with dioxygen (0.1 MPa) in the presence of stearate and a Co(II) acetylacetonate catalyst, which had high solubility in the reaction mixture at 80 \({}^{\circ}\)C [42]. For comparison, as part of this study, the ethylbenzene oxidation reaction was carried out using PS-NHPI-3 and CoCl\({}_{2}\) in benzonitrile, and the products obtained were acetophenone (S\({}_{\text{AP}}\) = 66.7%), 1-phenylethanol (S\({}_{\text{PEOH}}\) = 26.2%), and ethylbenzene hydroperoxide (S\({}_{\text{EBOOH}}\) = 7.1%). These results indicate that the addition of an ionic liquid makes the heterogeneous catalyst similar to a homogeneous catalyst. This is an important aspect of the SILP technique, which involves covering the inert carrier with an ionic liquid that contains dissolved forms of the transition metal catalyst [32]. Employing a catalytic system consisting of three separately introduced components (PS-NHPI-4, CoCl\({}_{2}\), and [emim][OcoSO\({}_{3}\)]; i.e., the PS-NHPI-4/CoCl\({}_{2}\)/[emim][OcoSO\({}_{3}\)] system described in Table 3 (entry 16) for the oxidation reaction led to 6.9% ethylbenzene conversion. This was a similar result to that obtained with the analogous integrated system, PS-NHPI-4@CoCl\({}_{2}\)@[emim][OcoSO\({}_{3}\)] (7.2%; entry 13), although the composition of the product mixture differed significantly between the two cases. Specifically, much greater amounts of ethylbenzene hydroperoxide (S\({}_{\text{EBOOH}}\) = 23.3%) and 1-phenylethanol (S\({}_{\text{PEOH}}\) = 40.0%) products were obtained using the PS-NHPI-4/CoCl\({}_{2}\)/[emim][OcoSO\({}_{3}\)] system.