Precious metals including copper, gold, and palladium can be dissolved in supercritical CO2 by oxidation with HNO3 and subsequent chelation with hexafluoroacetylacetone to form CO2-soluble metal beta-diketonate complexes. The oxidizing agent HNO3 is carried into the supercritical fluid phase by the CO2-soluble Lewis base tri-n-butyl phosphate (TBP) as a complex of the general form TBP(HNO3)(x)(H2O)(y). For the dissolution of Pd metal, a Lewis acid-base complex of the form TBP(HNO3)(1.0)(H2O)(0.4) is required. An and Cu can be oxidized with a lesser amount of HNO3 in the complex. This supercritical fluid dissolution technique provides a "dry" method for recovering precious metals from abandoned electronics and spent catalysts with minimum waste generation.