DOE OSTI2019
Electrochemical and chemical studies reveal that the amido complex (PNH x P)Fe(CO)(H)(X) (FeN 1, x = 0, X = 0; Fe(H)(NH) 2, x = 1, X = H; PNHP = bis[2-(diisopropylphosphino)ethyl]amine) is active for the electrocatalytic oxidation of isopropanol. At room temperature, the amido FeN 1 dehydrogenates isopropanol to form acetone. The resulting amino hydride complex Fe(H)(NH) 2 is subsequently oxidized by one electron at a low potential (–0.74 V versus ferrocene/ferrocenium, Fc o/+ ) in tetrahydrofuran. In the presence of strong base (phosphazene base P 2 -Et, Et-N = P 2 (dma) 5 , P2), this oxidation process becomes a two-electron, two-proton process that regenerates FeN 1. FeN 1 is active for the electrooxidation of isopropanol in the presence of strong base (i.e., P2) with an onset potential near –1 V versus Fc o/+ . By cyclic voltammetry, fast turnover frequencies of 1.7 s –1 for isopropanol oxidation are achieved with FeN 1. Lastly, controlled potential electrolysis studies confirm that the product of isopropanol electrooxidation is acetone, generated with high Faradaic efficiency (~100%).
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗