title: An oxygen evolution Co-Ac catalyst--the synergistic effect of phosphate ions.
abstract: Formation of an amorphous cobalt based oxygen evolution catalyst called Co-Pi has been recently reported from a neutral phosphate buffer solution containing Co(2+). But the concentration of Co(2+) is as low as 0.5 mM due to poor solubility of a cobalt salt in phosphate medium. In the present study, a cobalt acetate based oxygen evolution catalyst (Co-Ac) is prepared from a neutral acetate buffer solution, where the solubility of Co(2+) is very high (>100 times in comparison with phosphate buffer solution). The Co-Ac possesses better catalytic activity than the Co-Pi with an additional advantage of easy bulk scale preparation. The comparative studies on the oxygen evolution reaction (OER) activity of Co-Ac and Co-Pi in phosphate and acetate buffer electrolytes reveal that the Co-Ac exhibits enhanced synergistic catalytic activity in phosphate solution, probably due to partial substitution of acetate in the catalyst layer by phosphate, resulting in the formation of a Co-Ac-Pi catalyst.
authors: Department of Inorganic and Physical Chemistry Indian Institute of Science, Bangalore - 560012, India. muni@ipc.iisc.ernet.in.
authors: Ahamed
authors: A
authors: Irshad
authors: Nookala
authors: N
authors: Munichandraiah