Synthesis, Characterization, and Reaction Studies of a PVP-Capped Platinum Nanocatalyst Immobilized on Silica

Abstract

An immobilized platinum nanocatalyst was prepared by first functionalizing the surface of activated silica with poly(vinylpyrrolidone) (PVP) and then reducing encapsulated platinum ions in the presence of these functionalized supports to form nanoparticles. Surface functionalization was monitored by infrared spectroscopy and surface area measurements, and the resulting nanocatalyst was characterized using transmission electron microscopy (TEM) and X-ray diffraction (XRD). Platinum nanoparticle size was determined to be approximately 5 nm based on TEM and XRD measurements. Catalytic activity of this material for the hydrogenation of cyclohexanone was found to be greater than that of unsupported colloidal PVP-capped platinum nanocatalysts. In addition, the immobilized nanocatalyst displayed no change in activity after being recycled. Taken together, these results clearly indicate advantages in the design of catalytic materials with desired properties.

Phase-segregated Pt–Ni chain-like nanohybrids with high electrocatalytic activity towards methanol oxidation reaction

“…It is not out of the expectation since the PVP was reported as the classical surfactant to prevent the agglomeration of the nanoparticles. 36,37 Scheme 1 depicts the formation mechanism of the phase-segregated Pt-Ni chain-like nanohybrids.…”

Synthesis of Highly Active and Thermally Stable Nanostructured Pt/Clay Materials by Clay-Mediatedin SituReduction

“…The development of novel Pt-based nanocomposites for highly functional materials with advanced properties and improved performance is a continuously expanding research topic. Efforts have already been made to attach Pt nanoparticles onto 1D or 2D supporting materials such as carbon nanotubes, , carbon nanofibers, graphene, silica nanoparticles, and inorganic clay − in order to construct new hybrids. Although the fabrication of these nanocomposites was successful, most approaches involve complicated modifications using organic surfactants or polymeric stabilizers. − However, the addition of organic dispersants could have negative consequences such as reduced Pt activity and/or unwanted organic residues during various applications.…”

Shaped platinum nanoparticles directly synthesized inside mesoporous silica supports

“…Preparation of Pt nanoparticles on the silica support, which was a priori functionalized with PVP, was previously reported, but direct nucleation on the support was not confirmed. 41 Direct nucleation and overgrowth of Pt nanoparticles on the silica support were checked by monitoring the reacting solution during the synthesis. After the three reacting components, i.e., SBA-15, MPTMS, and the Pt precursor, were mixed at 120 °C, the temperature was increased to 230 °C and held there for 30 min.…”