Pluronic p123

The SBA-15 support was prepared via hydrothermal synthesis, according to a published procedure [46 (link)]. Pluronic P123 (Poly(ethylene glycol)-block-Poly(ethylene glycol)-block-Poly(ethylene glycol)-block) copolymer was used as a surfactant and TEOS as a source of silicon. The reactant mixture consisted of water, 0.7 M hydrochloric acid (performed with 35–38% HCl, POCH S.A. Gliwice), Pluronic P123 (Sigma-Aldrich) and TEOS (Sigma-Aldrich), at the molar ratios: 1SiO₂: 0.005Pluronic P123: 1.45HCl: 124H₂O. After dissolving Pluronic P123 in an HCl solution, the source of silica was added. The mixture was stirred at 308 K for 20 h, moved into a PP bottle, and heated without stirring at 373 K for 24 h. The solid was filtered, washed with deionized water, and dried at room temperature. The template was removed by calcination at 773 K for 8 h in the air in steady state conditions (temperature rate 6 K min⁻¹).

Nb-free and Nb-containing mesoporous materials of SBA-15 structure were synthesized according to the modified procedure previously reported in [44 (link)], which is summarized in Figure S1 (supporting information). In a typical synthesis using the nonionic triblock copolymer surfactant Pluronic P123 (EO₂₀PO₇₀EO₂₀, MW = 5800, from Aldrich), 4.65 g of Pluronic P123 was dissolved in 167 mL of water (milli Q) with 9.2 g of HCl 37% and 4.65 g of n-butanol, and the mixture was stirred for 1 h. Next, 10 g of tetraethyl orthosilicate (TEOS) was added, and the resulting white liquid was kept under stirring for 24 h. Then, the solution was transferred to a Teflon-coated stainless-steel autoclave, and the synthesis took place under static hydrothermal conditions at 100 °C for 24 h. The solid formed was filtered and washed with 2 L of deionized water, drying it at 60 °C for 12 h. This will be named SBA.
In the case of Nb-doped SBA-15, named SBA(Nb), a 2 wt% of Nb (using ammonium niobate (V) oxalate hydrate as the Nb-precursor) was co-added, with the remaining TEOS quantity following the same synthesis procedure as that used for the preparation of SBA-15.
Finally, the samples were calcined in order to eliminate the remaining organic template. In all cases, the samples were heat-treated at 550 °C for 4 h (1.5 °C/min ramp) in an open-air muffle.

Tetraethyl orthosilicate (TEOS) (≥99.0%), hydrochloric acid (purum p.a. ≥32.0%), Pluronic P-123, (3-aminopropyl) triethoxysilane (APTES) (99%), sodium dodecyl sulfate (≥99.0%), anhydrous toluene (99.8%), and sulindac (≥98.0%) were supplied by Merck Life Science Sp.z.o.o., an affiliate of Merck KGaA, Darmstadt, Germany (Poznań, Poland). Chloroform (p.a. ≥98.5%), sodium chloride (pure p.a.), dipotassium phosphate (pure p.a.), and sodium hydroxide 0.1 mol/L (0.1 N) were purchased from Avantor Performance Materials Poland (Gliwice, Poland).