Tunable Low Density Palladium Nanowire Foams*

Nanostructured metal foams offer exciting potential for applications in diverse fields such as biomedical, aerospace and chemical engieering. We have fabricated palladium nanowire foams with opportunities in catalysts, fuel cells, and hydrogen storage technologies using a cross-linking and freeze-drying technique. These foams have a tunable density down to 0.1% of the bulk, and a surface area to volume ratio of up-to 1.54×10⁶ :1 m^-1. These foams exhibit highly attractive characteristics for hydrogen storage, in terms of loading capacity, rate of absorption and heat of absorption.[1] The hydrogen absorption/desorption process is hysteretic in nature, accompanied by substantial lattice expansion/contraction as the foam converts between Pd and PdH_x.
[1] D. A. Gilbert, E. C. Burks, S. V. Ushakov, P. Abellan, I. Arslan, T. E. Felter, A. Navrotsky, and Kai Liu, Chemistry of Materials, DOI:10.1021/acs.chemmater.7b03978 (2017).