Electrochemical Hydrogen Production in Acidic Water by an Azadithiolate Bridged Synthetic Hydrogenese Mimic: Role of Aqueous Solvation in Lowering Overpotential

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• 作者：Subal Dey ; Atanu Rana ; Somdatta Ghosh Dey ; Abhishek Dey
• 刊名：ACS Catalysis
• 出版年：2013
• 出版时间：March 1, 2013
• 年：2013
• 卷：3
• 期：3
• 页码：429-436
• 全文大小：430K
• 年卷期：v.3,no.3(March 1, 2013)
• ISSN：2155-5435

文摘

An inherent problem stalling the development of a H₂-based global energy economy is the unavailability of efficient functional catalysts that can function in aqueous media. A Fe鈥揊e hydrogenase mimic is investigated for electrocatalytic hydrogen generation in aqueous medium. H₂ is produced from acid water (pH <3) by a Fe鈥揊e hydrogenase mimic immobilized on graphite surfaces. These catalysts are known to reduce H⁺ at very negative potentials in organic solvents. However, in aqueous medium, the H⁺ reduction potential is shifted to much more positive values. The catalyst shows a turnover frequency of 6400 s^鈥? at 鈭?.5 V and an onset potential of 鈭?.36 V vs NHE. Prolonged electrolysis shows that the catalyst has a turnover number 10⁸ and a Faradaic efficiency > 95%. Even at pH 2, that is, [H]⁺ = 0.01 N, I_cat/[蟿] > 400 s^鈥? is obtained. The catalyst can be immobilized on cheap carbon electrodes, used in domestic Zn-Carbon dry batteries, to generate H₂ from acid aqueous solutions.

Keywords:

hydrogen evolution reaction; iron hydrogenase; bio-inspired catalysis