Iron, Cobalt and Nickel complexes with N4-donor ligands catalysts for the CO2 photoreduction

Identifier:  imarina:9378596

Handle: https://hdl.handle.net/20.500.11797/imarina9378596

Authors:  El Aouni, Nassima; Aghmiz, Ali; Reguero, Mar; Masdeu-Bulto, Anna M

Abstract:
Iron(II), cobalt(II) and nickel (II) complexes bearing phenanthroline- and bipyridine-bis(imino) ligands have been prepared and tested as catalysts for the photoreduction of CO2 2 at atmospheric pressure and room temperature in the presence of a photosensitizer (PS) and sacrificial electron donor (SD) producing mixtures of CO and H2. 2 . The best results were obtained with a Fe(II) catalyst using triethanolamine/1,3-dimethyl-2-phenyl-2,3dihydro-1H-benzoimida-zole (BIH) in acetonitrile using a blue LED irradiation with [Ru(bpy)3]PF6]2 3 ]PF 6 ] 2 (bpy = 2,2 '- '- bipyridine) as PS. With this system, a mixture of CO/H2 2 (68/32) was obtained with a turnover number (TONCO CO 166, 24 h). Analogous Co(II) and Ni(II) complexes produced H2 2 as a major product. Cyclic voltammetry demonstrates that the electrons uptake is centered on the ligand. Computational calculations allow to propose the most stable location of the electrons.