Impact of sonochemistry on synthesis and physicochemical properties of heterogeneous catalysts for gaseous environmental abatement

The phenomenon of acoustic cavitation (the formation, oscillation, growth, and implosive collapse of tiny bubbles filled with dissolved gases and liquid vapor) generated by the irradiation of a liquid medium with ultrasound has established itself as an important tool in various branches of chemistry. The use of ultrasonic irradiation in chemical processes is known as “sonochemistry.” Among the applications of sonochemistry, the involvement of ultrasound in materials synthesis can provide a fast, straightforward method for preparing heterogeneous catalysts compared to conventional methods, thanks to the chemical and physical effects of acoustic cavitation (excited species, shockwaves, microjets, sonoluminescence). The catalytic processes involved in the transformation of greenhouse gases are attracting greater attention for their role in addressing the major environmental problem of global warming. The application of ultrasonic irradiation results in catalysts with enhanced structural, textural, and morphological properties, including specific surface area, particle size distribution, and dispersion of the active phase on the support. Hence, ultrasonic-assisted synthesis of catalysts yields materials with better activity and stability than those obtained by classical preparation methods, which is particularly important for the development of heterogeneous catalysis.