Electrolytic reduction of Nantong coal and model compounds with oxygenic functional groups in an aqueous NaCl solution

Electrolytic reductions of oxygenic functional groups (OFGs) on coal surface and coal model compounds with OFGs in an aqueous NaCl solution are studied by electrochemical methods combined with GC/MS, GC and FTIR analyses. Different electrode reactions, their corresponding potentials and dynamic equations during the processes are investigated. The results show that benzoic acid, benzaldehyde, benzalcohol and hypnone are reduced to benzaldehyde and benzalcohol, methoxybenzene and benzalcohol, toluene and styrene, respectively, at the cathode. The corresponding electrode potentials and dynamic equations are determined. The electrolytic reduction also leads to an increase in the contents of hydroxyl groups and aliphatic moieties and a corresponding decrease in those of carboxyl and carbonyl groups in Nantong coal, a high-sulfur coal, an enhancement in the flotation desulfurization of the coal. ER also reduces organic sulfur and FeS2 in the coal.