Bonding of chlorophenols on iron and aluminum oxides

摘要: The adsorption of 10 chlorophenols on synthetic, naturally occurring iron and aluminum oxides was studied to elucidate the mechanism binding relative bond strength chlorine-substituted phenols identified by spectroscopic methods. Chlorophenolates were found be chemisorbed oxide surfaces via an inner-sphere coordination. Chlorophenols also bonded weak physical forces (H bonding condensation), but these types only when occurred from vapor phase onto dry surfaces. Physisorbed chlorophenols, unlike molecules, readily removed washing with water. Poorly crystallized showed similar mechanisms chlorophenol binding, although for chlorophenolate stronger than that oxide. Only physically adsorbed detected crystalline gibbsite, suggesting dominant (001) crystal face, surface hydroxyl groups doubly coordinated Al, not specifically reactive chlorophenols. Chemisorption, however, iron, geothite. From extent perturbation aromatic ring electrons, chlorophenolates correlate Lewis basicity phenolate anions (the higher pK{sub {alpha}} chlorophenols,more » bond). Nevertheless, amount noncrystalline at controlled pH 5.4 limited deprotonation lower a}, more adsorption).« less