Self‐Assembly of Palladium Nanoparticles on Periodic Mesoporous Organosilica Using an In Situ Reduction Approach: Catalysts for Ullmann Reactions in Water

Abstract

A Si--H functionalized phenyl-bridged periodic mesoporous organosilica [H-PMO(Ph)] is synthesized via a surfactant-directed assembly approach. Pd nanoparticles are then immobilized onto the PMO catalyst [Pd/H-PMO(Ph)] by a Si--H in situ reduction method. The Ullmann reaction, in water as medium, is used to investigate the catalytic performance of Pd/H-PMO(Ph). The results show that the Pd/H-PMO(Ph) catalyst has excellent catalytic activity and selectivity, which can be attributed to synergetic effects derived from the highly dispersed catalytic species and the hydrophobic microenvironments. Furthermore, the catalyst could be conveniently recovered and recycled five times without significant loss of activity and selectivity.

Synthesis of Pd/SBA-15 catalyst employing surface-bonded vinyl as a reductant and its application in the hydrogenation of nitroarenes

“…Li et al rst synthesized a Si-H functionalized phenyl-bridged periodic mesoporous organosilica (PMO). 26 Then, Pd nanoparticles were immobilized onto the PMO by a Si-H in situ reduction method. The resulting catalysts showed excellent catalytic activity and selectivity for the Ullmann reaction in water.…”

Piperazine-functionalized ordered mesoporous polymer as highly active and reusable organocatalyst for water-medium organic synthesis

“…All the isotherms were of type V, indicative of weak absorbent-absorbate interaction. 25 However, the adsorption capacity of PP-MP-2 for toluene (13 wt%) was much higher than that of water (5.7 wt%). This result demonstrated that its mesopore surface was hydrophobic, leading to selective adsorption for organic reactants.…”

Water-medium organic synthesis over active and reusable organometal catalysts with tunable nanostructures

“…20 Furthermore, mass transfer limitations in the heterogeneous catalytic systems were more pronounced owing to the spatial hindrance of the solid matrix as well as the low solubility of organic reactants in water. 21 To overcome these barriers, a variety of novel strategies have been developed to design powerful organometal catalysts via controlling the morphology and porous structure, adjusting the location and interaction of the active sites with the supports, and engineering the surface chemistry. Recent developments in nanoscale supports such as mesoporous materials and nanoparticles have supplied a promising way for designing powerful heterogeneous organometal catalysts.…”