Potassium tetrachloropalladate is the palladium source named in most shape-controlled nanocrystal syntheses: reduction with ascorbic acid or sodium borohydride in the presence of PVP and potassium bromide gives palladium nanocubes, octahedra and nanowires, and seeded growth from these gives palladium–platinum core–shell electrocatalysts for oxygen reduction and formic acid oxidation. The same salt is reduced onto carbon to make Pd/C electrocatalysts and hydrogenation catalysts.
In coordination and organometallic chemistry it is the usual precursor for dichloropalladium(II) complexes made in water or alcohol (PdCl₂(ligand)₂ with phosphines, diimines, pyridines or thioethers), for cyclometalated palladium complexes, for palladium(II) complexes of amino acids, peptides and nucleobases, and for the allylpalladium chloride dimer [Pd(η³-C₃H₅)Cl]₂, which is prepared from tetrachloropalladate, allyl chloride and carbon monoxide in aqueous methanol.
It is also used for aqueous-phase Suzuki and Heck couplings, for the deposition of palladium onto electrodes and membranes, as a palladium standard in analysis, and, like the sodium salt, as a sensitiser in palladium and platinum–palladium photographic printing.