Hydrogen Production Using Nickel Electrocatalysts with Pendant Amines: Ligand Effects on Rates and Overpotentials
Citations Over TimeTop 10% of 2013 papers
Abstract
A Ni-based electrocatalyst for H2 production, [Ni(8PPh2NC6H4Br)2](BF4)2, featuring eight-membered cyclic diphosphine ligands incorporating a single amine base, 1-para-bromophenyl-3,7-triphenyl-1-aza-3,7-diphosphacycloheptane (8PPh2NC6H4Br) has been synthesized and characterized. X-ray diffraction studies reveal that the cation of [Ni(8PPh2NC6H4Br)2(CH3CN)](BF4)2 has a distorted trigonal bipyramidal geometry. In CH3CN, [Ni(8PPh2NC6H4Br)2]2+ is an electrocatalyst for reduction of protons, and it has a maximum turnover frequency for H2 production of 800 s–1 with a 700 mV overpotential (at Ecat/2) when using [(DMF)H]OTf as the acid. Addition of H2O to acidic CH3CN solutions of [Ni(8PPh2NC6H4Br)2]2+ results in an increase in the turnover frequency for H2 production to a maximum of 3300 s–1 with an overpotential of 760 mV at Ecat/2. Computational studies carried out on [Ni(8PPh2NC6H4Br)2]2+ indicate the observed catalytic rate is limited by formation of nonproductive protonated isomers, diverting active catalyst from the catalytic cycle. The results of this research show that proton delivery from the exogenous acid to the correct position on the proton relay of the metal complex is essential for fast H2 production.
Related Papers
- → Ni Foam-Supported Fe-Doped β-Ni(OH)2 Nanosheets Show Ultralow Overpotential for Oxygen Evolution Reaction(2019)308 cited
- → High-Performance Electrochemical CO2 Reduction Cells Based on Non-noble Metal Catalysts(2018)115 cited
- → Improved HER Catalysis through Facile, Aqueous Electrochemical Activation of Nanoscale WSe2(2018)80 cited
- → Critical Overpotential and Induction Time of Dendritic Growth(1974)40 cited
- → The effect of some sulfur-containing additives on the initial cathode overpotential during copper electrodeposition(1973)5 cited