Large-scale engineered synthesis of BaTiO₃ nanoparticles using low-temperature bioinspired principles.

We report here a robust, large-scale synthesis of BaTiO₃ nanopowders using a bioinspired process that first was developed on a much smaller scale. The most advantageous points of this protocol are that it takes place at nearly room temperature (25°C), overcomes many limitations encountered in other scale-up processes (such as the need for external drivers, e.g.

High-efficiency aminocarbonylation by introducing CO to a pressurized continuous flow reactor.

Halogenated aryl carboxylic acids were efficiently converted to the corresponding dicarboxylic acid monoamides by a one-step Pd-catalyzed aminocarbonylation in a micro/meso fluidic continuous flow reactor (X-Cube) operated at high pressure and high temperature with CO gas introduction. Reaction parameters (solvent, base, catalyst, pressure, temperature) were rapidly optimized in the reactions, which required less than 2 min. The method gave improved results over comparable batch techniques and is also suited to automated parallel syntheses of compound libraries.

Adsorption and co-adsorption of ethylene and carbon monoxide on silica-supported monodisperse Pt nanoparticles: volumetric adsorption and infrared spectroscopy studies.

The adsorption of carbon monoxide and ethylene, and their sequential adsorption, was studied over a series of Pt/SBA-15 catalysts with monodisperse particle sizes ranging from 1.7 to 7.1 nm by diffuse-reflectance infrared spectroscopy and chemisorption.

Rhodium nanoparticles from cluster seeds: control of size and shape by precursor addition rate.

The size-tunable synthesis of poly(vinylpyrrolidone)-stabilized cuboctahedral rhodium nanoparticles with mean diameters ranging between 3-7 nm and multipod structures was accomplished using seeded growth methods. Isotropic PVP-capped 2.9 nm seeds were prepared by ligand exchange on rhodium-triphenylphosphine metal-organic clusters.

Structure sensitivity of vibrational spectra of mesoporous silica SBA-15 and Pt/SBA-15.

The vibrational properties of mesoporous silica (SBA-15) were investigated by deep ultraviolet (UV) Raman and infrared spectroscopies with and without the presence of platinum nanoparticles in the mesopores that were incorporated by sonication. Raman and IR spectral line assignments were made by comparison to amorphous silicas. This procedure permitted identification of vibrations of longitudinal (LO) and transverse (TO) optical lattice modes, the presence of Si-OH, and vibrational modes associated with the presence of three-, four-, and six-membered siloxane rings.

Hydrothermal growth of mesoporous SBA-15 silica in the presence of PVP-stabilized Pt nanoparticles: synthesis, characterization, and catalytic properties.

A novel high surface area heterogeneous catalyst based on solution phase colloidal nanoparticle chemistry has been developed. Monodisperse platinum nanoparticles of 1.7-7.

Precise control of the Pt nanoparticle size by seeded growth using EO13PO30EO13 triblock copolymers as protective agents.

Here, we report an efficient way to produce homogeneous Pt nanoparticles within a well-defined size range (3.5-6.6 nm) as a result of the seeded growth procedure using Pluronic L64 polymer capping agent.

Sol-gel synthesis of ordered mesoporous alumina.

Well-ordered mesoporous alumina materials with high surface area and a narrow pore size distribution were synthesized using a sol-gel based self assembly technique.

Radial anisotropic growth of rhodium nanoparticles.

In this contribution, we report the synthesis of rhodium multipods that result from a homogeneous seeded growth mechanism. Small Rh nanocrystal seeds were synthesized by the reduction of RhCl3 in ethylene glycol in the presence of PVP. These seed particles could be subsequently used, without isolation, to form larger rhodium nanoparticles.