Five supported heterogeneous Pd catalysts have been prepared, characterized and found to be active and selective in the Suzuki-Miyaura coupling of boronic acids, and aromatic iodo and bromo compounds to form the corresponding biaryls in high selectivities. Reaction conditions, namely, the solvent, base ( triethylamine, Na2CO3, Cs2CO3) and tetrabutylammonium chloride as an additive are shown to have profound effects on catalyst performance.