Nanostella'rs Catalyst Synthesis Methodologies

There are many methods for the synthesis of metal particles. One versatile method attracting considerable attention in recent years involves the formation of metal nanoparticle colloids via use of chemical reduction in the presence of stabilizers. Isolated metal nanoparticles with sizes ranging from 1 to 50 nm can be formed and stabilized by means of steric and/or electrostatic effects. The large number of available stabilizers (ligands, polymers, surfactants) and chemical reducing agents (inorganic and organic; solid, liquid, or gas), coupled with the available synthesis parameters (temperature, pH, reaction time) provide a tremendous range of procedures that can be utilized for the generation of colloidal nanoparticles. Although optimized colloidal methods offer increased control over particle size and composition, they tend to be costly and can be difficult to use as metal sources for deposition onto support materials. This difficulty is due to problems encountered when generating concentrated colloids and issues that are encountered during deposition, such as lack of penetration into support pores and agglomeration into larger particles.

Traditional synthesis processes for generating supported metal catalysts have focused on impregnation techniques that involve direct deposition of metal salts onto a support material followed by subsequent treatment to allow fixation of the metal. Although cost effective, impregnation approaches typically do not offer structural and compositional control. Such control is particularly important when specific nanoparticle sizes and/or compositions are desired.

As part of Nanostellar's Rational Catalyst Design technology, we have developed an array of proprietary nanoparticle synthesis techniques that combine key aspects of colloidal nanoscience with more commercially viable processes to allow production of large quantities of supported metal nanoparticles with tailored properties. Nanostellar's synthesis methods are particularly well suited for the generation of supported nanoparticles containing multiple metal species with intimate metal-metal contact (e.g., nanocomposites or nanoalloys). Our ability to synthesize supported nanoparticles with increased control over structure and composition is a key component to the RCD process, allowing testing and verification of targeted catalytic properties and scale-up for product manufacturing.