Ligand-enhanced reduction of perchlorate in water with heterogeneous Re-Pd/C catalysts

Two methods to prepare new bimetallic heterogeneous catalysts for the reduction of perchlorate in water with dihydrogen are reported. The first method by by impregnating 5 wt % Pd on activated carbon powder with one of the complexes trans-[[Re[O.sub.2][(py-X).sub.4]].sup.+] (py-X = 4-substituted pyridine; X = H, Me, OMe, N[Me.sub.2]) showed evidence of facile formation of perrhenate from handling under ambient conditions while second method with 2 equiv of of dimethylaminopyridine per Re is especially active and stable up to pH 4.5.