The reduction of carbon dioxide employing 1,4,7,10-tetramethyl-1,4,7,10 tetraazacyclododecane nickel(II) as a electron relay catalyst

Abstract

Photolysis of a mixture of [Ni(Me 4[12]aneN 4)(H 2O)] 2+, [Ru(bipy) 3] 2+, ascorbate and carbon dioxide resulted in the formation of carbon monoxide, hydrogen and formic acid. The electrolysis of [Ni(Me 4[12]aneN 4)(H 2O)] 2+, in the presence of carbon dioxide and various electrolytes resulted in the formation of formic acid. More formic acid was formed in the presence of sodium perchlorate than sodium chloride. [Ni(Me 4[12]aneN 4)(H 2O)] 2+, preferentially reduces carbon dioxide versus a proton in aqueous solution regardless whether this nickel(I) complex is generated electrochemically or photochemically. This photo or electro generated nickel(I) complex also interacts strongly with CO and ascorbate but not with a proton above the pH of 4.