Synthesis of New RuO₂@SiO₂ Composite Nanomaterials and their Application as Catalytic Filters for Selective Gas Detection

Abstract

RuO 2 @SiO 2 nanomaterials have been prepared using hybrid mesostructured silica (EtO) 2 P(O)(CH 2 ) 3 SiO 1.5 /xSiO 2 (x = 9, 16) by anchoring the metal precursor [Ru(COD)(COT)] (COD = 1, 3-cyclooctadiene, COT = 1, 3, 5-cyclooctatriene) within the pores of the organized silica matrix taking profit of the phosphonate moieties followed by i) decomposition under dihydrogen atmosphere at room temperature in THF to achieve ruthenium nanoparticles containing materials and ii) a solid state thermal treatment at 450°C under air. The Ru and RuO 2 nanoparticles containing materials have been characterised by elemental analysis, Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD), nitrogen sorption measurements and 31 P and 13 C Nuclear Magnetic Resonance (NMR). The so-obtained RuO 2 @SiO 2 nanomaterials were evaluated as catalytic filters when deposited onto gas sensors for the preferential detection of propane in a multicomponent gas mixture propane/carbon monoxide/nitrogen dioxide.

[Ru(0)]@SiO2 and [RuO2]@SiO2 Hybrid Nanomaterials: From Their Synthesis to Their Application as Catalytic Filters for Gas Sensors

“…Note that these new hybrid materials provide a selectivity in propane detection that is considerably higher than that measured with RuO 2 @SiO 2 materials prepared by filling of preformed organized SiO 2 mesoporous materials under quite similar experimental conditions (e.g., a selectivity of 3.0 for a [Ru]/ [Si] ratio of 0.11). [4] The excellent selectivity efficiency by the novel hybrid materials presented here is assumed to be closely related to their particularly high porosity, which allows more efficient access to the catalytic sites.…”

“…This behavior was previously demonstrated with another type of [RuO 2 ]@SiO 2 hybrid nanomaterials, prepared by filling of preformed mesoporous materials, and implemented as external filters. [4] It obviously results from the catalytic properties of RuO 2 that selectively oxidizes CO into CO 2 , which remains undetected by the sensitive layer, leaving the hydrocarbon content unaltered. The efficiency of the propane discrimination is dependent on the metal content of the hybrid [RuO 2 ]@SiO 2 materials.…”

Proton Conductivity versus Acidic Strength of One‐Pot Synthesized Acid‐Functionalized SBA‐15 Mesoporous Silica

“…[70] Acid-Functionalized SBA-15: Pluronic P123 (8.0 g, 1.38 mmol) was dissolved in an aqueous solution of HCl (320 mL) (pH = 1.5). TEOS (16.8 g, 80.77 mmol) was added together with the appropriate amount of the selected precursor [(EtO) 3 Si(CH 2 ) 3 -X], which was chosen according to the nature and functional degree of the functionalized material that we required.…”

“…SBA-PO(OEt) 2 (1/9) (3.0 g, 3.90 mmol) or SBA-PO(OEt) 2 (1/19) (3.0 g, 2.18 mmol) was treated with aqueous HCl (50 mL, 12 n) while stirring at 100°C over 24 h. The solid product was recovered by filtration, washed several times with water and ethanol and then dried at 70°C under vacuum. [27,70] The prepared samples were denoted as SBA-PO(OH) 2 (1/9) and SBA-PO(OH) 2 (1/19).…”

Organometallic Nanoparticles of Metals or Metal Oxides

“…Well-dispersed nanoparticles could be obtained in the silica matrix giving rise to hybrid materials displaying an interesting behaviour as catalytic filters to enhance the selectivity of gas sensors [100].…”