Palladium(II) nitrate dihydrate serves primarily as a catalyst and reactant in various chemical processes and applications. Its primary purpose is to facilitate doping activated carbon for improved catalysis and support hydroxyapatite-loaded palladium nanoclusters during the hydrolysis of ammonia-borane. It plays a critical role in catalyzing the selective hydrogenation of compounds such as 1-heptyne and naphthalene, especially when used with porous MIL-101 coordination polymer supports. Furthermore, it acts as a precursor in the preparation of advanced catalysts, such as platinum-palladium/carbon alloy nanocatalysts for enhanced oxygen reduction reactions in fuel cells, and Cu-Pd alloy thin films on titanium substrates through co-electrodeposition. Additionally, it is instrumental in forming palladium-supported catalysts on vertically aligned multi-walled carbon nanotubes for microwave-assisted Heck reactions and developing di-phenyl sulfide-modified Pd/TiO2 catalysts aimed at acetylene hydrogenation.