Liquid-fed aerosol reactors for one-step synthesis of nano-structured particles

Abstract

Aerosol technology is the key process for large-scale production of nano-structured materials such as carbon black, titania and silica. The understanding of gas-phase synthesis was transferred successfully from classic vapor-fed f lames to liquid-fed aerosol reactors, enabling now also the one-step production of demanding and highly functional products. Such aerosol-derived nano-structured metal oxides, mixed metal oxides, and metals on metal oxides find application in the fields of catalysis, sensors, fillers, and electronics, and have advanced the research and development of these reactors in recent years. The four main spray methods include spray pyrolysis in a tubular reactor (SP), spray pyrolysis using a vapor f lame reactor (VFSP), the emulsion combustion method (ECM) and f lame spray pyrolysis (FSP). These methods are discussed and key concepts are compared such as the energy source driving the solvent/fuel evaporation and precursor reaction, final particle formation. Advances in fundamental understanding, scaling and simulation are highlighted. Specific strategies for the production of homogeneous products are presented in context with existing methods and specific applications. Finally, research needs are discussed with respect to new flame-made materials, instrumental strategies for their production and process optimization, including diagnostic techniques and process simulation.