Minimal Proton Channel Enables H2 Oxidation and Production with a Water-Soluble Nickel-Based Catalyst

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• 作者：Arnab Dutta ; Sheri Lense ; Jianbo Hou ; Mark H. Engelhard ; John A. S. Roberts ; Wendy J. Shaw
• 刊名：Journal of the American Chemical Society
• 出版年：2013
• 出版时间：December 11, 2013
• 年：2013
• 卷：135
• 期：49
• 页码：18490-18496
• 全文大小：414K
• 年卷期：v.135,no.49(December 11, 2013)
• ISSN：1520-5126

文摘

Hydrogenase enzymes use first-row transition metals to interconvert H₂ with protons and electrons, reactions that are important for the storage and recovery of energy from intermittent sources such as solar, hydroelectric, and wind. Here we present Ni(P^Cy₂N^Gly₂)₂, a water-soluble molecular electrocatalyst with the amino acid glycine built into the diphosphine ligand framework. Proton transfer between the outer coordination sphere carboxylates and the second coordination sphere pendant amines is rapid, as observed by cyclic voltammetry and FTIR spectroscopy, indicating that the carboxylate groups may participate in proton transfer during catalysis. This complex oxidizes H₂ (1鈥?3 s^鈥?) at low overpotentials (150鈥?65 mV) over a range of pH values (0.1鈥?.0) and produces H₂ under identical solution conditions (>2400 s^鈥? at pH 0.5). Enzymes employ proton channels for the controlled movement of protons over long distances鈥攖he results presented here demonstrate the effects of a simple two-component proton channel in a synthetic molecular electrocatalyst.