Noble Metal Aerogels

Abstract

Noble metals offer a wide range of applications including catalysis, energy storage and conversion, and sensing. The formation of freestanding noble metal aerogels (NMAs) with high specific surface area (SSA) and hierarchical porosity confers significant advantages for conductivity, mass transfer properties, reaction specificity, and strength-to-weight ratio compared to their bulk metal counterparts. This chapter reviews two-step sol–gel formation of noble metal monolithic aerogels from monodisperse nanoparticles, one-step direct solution-based reduction, and non-sol–gel synthesis techniques of dealloying, combustion, and templating approaches to include biotemplated noble metal aerogel composites and salt-templated structures. Gold, silver, palladium, and platinum are primarily considered, as well as their applications for catalysis, energy systems, and sensing.