2D Mesoporous Channels of PMO; a Platform for Cluster-Like Pt Synthesis and Catalytic Activity in Nitrophenol Reduction

Abstract

Thiourea-bridged organosiloxane is used to synthesize a periodic mesoporous organosilica (PMO). Since this PMO has an S-enriched surface, owing to thiourea functional groups, it exhibits strong coordination toward Pt ions, and it shows a high tunability in the Pt nanoparticles size. This hybrid mesoporous material is employed as a catalyst in the efficient reduction reaction of 4-nitrophenol to 4-aminophenol at room temperature in an aqueous media.

Supported copper on a diamide–diacid-bridged PMO: an efficient hybrid catalyst for the cascade oxidation of benzyl alcohols/Knoevenagel condensation

“…Aer that, tetraethyl orthosilicate (TEOS, 2.8 mL) was added dropwise and stirred at 40 C for 24 h, and was then increased to 100 C and aged at this temperature for 48 h without stirring. Finally, the white precipitate was separated from the mixture, washed with distilled water and EtOH, and dried at 80 C for 6 h. 85,86 In the following, the product obtained in acidic medium was under Soxhlet extraction conditions using EtOH, as solvent, for 72 h.…”

Highly Dispersed Pt Catalysts on Hierarchically Mesoporous Organosilica@Silica Nanoparticles with a Core–Shell Structure for Polycyclic Aromatic Hydrogenation

“…One of the challenges of NMNP hydrogenation is agglomeration of active metals, which finally results in the consequent loss in activity due to their high surface energy . Thus, NMNPs supported on an appropriate nanostructured material would be an effective approach to achieve a favorable stability for active metals. − Mesoporous silica (MS) materials was discovered in early 1990, which could be modified with various functions over time to further improve their application in the catalytic process. − Furthermore, in the last two decades, the periodic mesoporous organosilicas (PMOs) became promising mesoporous nanostructured materials among others. PMOs are synthesized from the bridged organosilicas on precursors, [(RO) 3 Si-R-Si­(OR) 3 ], in the presence of a structure-directing agent (SDA) in either an acidic or basic environment. − The introduction of organic moieties in PMOs not only improves the physicochemical properties remarkably but also generates new active centers. , PMOs have especially made an important contribution in the design and improvement of novel catalysts, notably heterogeneous green catalysts.…”

Recent advanced development of metal-loaded mesoporous organosilicas as catalytic nanoreactors

“… 221 Pt 0 -loaded thiourea-bridged PMO was used for the reduction of 4-nitrophenol to 4-aminophenol. 222 In addition, the highly dispersed bimetallic Pt–Pd NPs were captured and stabilized by imine-bridged PMO with a SBA-15-like structure to form Pt–Pd-PMO-SBA-15. This catalyst was used in the hydrogenation of nitrobenzene.…”