A coordinatively saturated cobalt complex as a new kind catalyst for efficient electro- and photo-catalytic hydrogen production in purely aqueous media

作者：Peng, Qiu-Xia; Xue, Dan; Yang, Ling-Fen; Zhan, Shu-Zhong^*

来源：International Journal of Hydrogen Energy, 2017, 42(26): 16428-16435.

DOI：10.1016/j.ijhydene.2017.05.198

• Coordinatively saturated complex
• Molecular catalyst
• Proton or water reduction
• H-2 evolution

It has been shown that coordinatively unsaturated complexes can catalyze hydrogen production via an unstable hydride intermediate. Herein we present a new kind of water soluble catalyst based on a coordinatively saturated cobalt complex, [(phen)(2)Co(CN)(2)]ClO4 1 that is formed by the reaction of 1,10-phenanthroline (phen), Co(ClO4)(2)center dot 6H(2)O and tetracyanoethylene (TCNE). Under photoirradiation with blue light (lambda(max) = 469 nm) in air, together with [Ru(bpy)(3)]Cl-2 and ascorbic acid in a pH 5.5 aqueous solution, 1 possesses photocatalytic activity for water reduction to hydrogen with an initial turnover number (TON) of 1232H(2) per mol of catalyst at first 10 h, and this activity is sustained for at least 70 h. This can be attributed to that oxidative quenching by 1 (k(q) = 1.69 x 10(-10) M-1 s(-1)) dominates over reductive quenching to [Ru(bpy)(3)]Cl-2 by ascorbic acid (kq = 1.55 x 10(10) M(-1)s(-1) Additionally, 1 electrocatalyze hydrogen generation from a neutral water with a turnover frequency (TOP) of 1113.1 mol of hydrogen per mole of catalyst per hour (mol H-2/mol catalysts/h) at an overpotential (OP) of 838 mV. We hope this can afford a new method in proton or water reduction catalysis using coordinatively saturated complexes in purely aqueous media.

• 出版日期2017-6-29
• 单位华南理工大学