Preparation of Catalyst Colloids

Introduction

The particle size of the catalyst colloid is between the general molecular and heterogeneous catalyst particles, and belongs to the mesoscopic system. The catalyst colloid can only play a catalytic role when it is dispersed in the reaction system. In addition, the colloidal catalytic system has relative stability. This is due to the fact that the catalyst colloid particles are small, with large specific surface area and high free enthalpy, so it is easy to adsorb certain ions charged or solvated, thus preventing the coalescence of small particles.^[1]

Fig.1 A Janus colloid surfactant catalyst platform^[2]

Our Abilities

Preparation methods we offer

The members of the Alfa Chemistry development team have obtained master's degrees or above, and have rich experience in the research and development of catalyst colloids. Our preparation methods include but are not limited to:

• Dispersion Method — The bulk metal raw materials are micronized by physical methods such as mechanical pulverization and ball milling, and then dispersed in the medium.
• Chemical Reduction Method — The metal molecules are reduced to metal atoms by a reducing agent, and then agglomerated to obtain a colloid. In order to prevent particle agglomeration, it is usually necessary to add a protective agent to the medium. The protective agents used are mainly macromolecular polymers, organic long-chain thiols and surfactants.^[3]
• Impregnation Method — First, metal colloids are prepared, and then the metal colloids are supported on porous supports such as activated carbon(AC), SiO₂, Al₂O₃, etc. by impregnation to obtain supported colloidal catalysts.

Fig.2 Colloidal metal nanoparticles as a component of designed catalyst^[4]

Types of catalytic reactions

We are able to provide custom catalyst colloids for a wide variety of chemical reactions. Some reaction types are listed below. If the type of reaction you need is not included, please fill out the online form on the right, and our technical staff will contact you as soon as possible.

• Hydrogenation of olefins
• Selective partial hydrogenation of diolefins
• Nitrile water and reaction
• decarbonylation reaction
• Hydrogenation reaction initiated by visible light waves
• Amination reaction, etc.

Our Advantages

References

1. Shuwei Xia, et al. The Knowledge of Colloidal Catalyst. Chemistry. 2006.
2. Cho J, et al. Janus colloid surfactant catalysts for in situ organic reactions in Pickering emulsion microreactors. Green Chemistry. 2018.
3. Wenlong Qiao, et al. Preparation of Colloida lPd/γ-Al2O3 Catalyst by Chemical Reduction and Its Catalytic Properties for Furfural Decarbonylation. Petrochemical Technology. 2009, 38(3):244-248.
4. Jia C J, F Schüth. Colloidal metal nanoparticles as a component of designed catalyst. Physical Chemistry Chemical Physics Pccp. 2011.

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