Multi-component electrocatalyst for low-temperature fuel cells synthesized via sonochemical reactions

•This review presents recent advances in sonochemical preparation for electrocatalyst.•Physical effect of ultrasound in nanomaterials preparation is introduced.•Chemical effect of ultrasound in nanomaterials preparation is introduced.•Sonochemically prepared Pt- and Pd-based nanoparticles are highlighted.•Nanoparticles synthesized by sonochemistry and those by other methods are compared.

This review presents recent advances in multi-component electrocatalysts for low-temperature fuel cells (FCs) synthesized via sonochemical reactions. As a feasible approach to develop novel electrocatalysts that can overcome the many problems of the prevailing Pt electrocatalysts, Pt- or Pd-based alloy and core–shell M@Pt nanoparticles (NPs) have been pursued. Synthesizing NPs with desirable properties often turn out to be challenging. Sonochemistry generates extreme conditions via acoustic cavitation, which have been utilized in the syntheses of various Pt and Pd NPs and Pt- and Pd-based alloy NPs. Especially, it has been reported that several M@Pt core–shell NPs can be synthesized by sonochemistry, which is hard to achieve by other methods. The principles of sonochemistry are presented with examples. Also alloy NPs and core–shell NPs synthesized by sonochemistry and those by other methods are compared.