Covalent Attachment of the Water-insoluble Ni(P ^Cy ₂ N ^Phe ₂ ) ₂ Electrocatalyst to Electrodes Showing Reversible Catalysis in Aqueous Solution

Journal Article · Sat Oct 01 04:00:00 EDT 2016 · Electroanalysis

DOI:https://doi.org/10.1002/elan.201600306· OSTI ID:1347874

Rodríguez-Maciá, Patricia ^[1]; Priyadarshani, Nilusha ^[2]; Dutta, Arnab ^[3]; Weidenthaler, Claudia ^[4]; Lubitz, Wolfgang ^[1]; Shaw, Wendy J. ^[2]; Rüdiger, Olaf ^[1]

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1. Max Planck Institute für Chemische Energiekonversion, Stiftstr. 34-36 45470 Mülheim an der Ruhr Germany
2. Pacific Northwest National Laboratory, 902 Battelle Blvd. Richland WA 99354 USA
3. Pacific Northwest National Laboratory, 902 Battelle Blvd. Richland WA 99354 USA; Chemistry Department, IIT Gandhinagar, Ahmedabad 382424 India
4. Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany

Hydrogenases are a diverse group of metalloenzymes which catalyze the reversible conversion between molecular hydrogen and protons at high rates. The catalytic activity of these enzymes does not require overpotential because their active site has been evolutionarily optimized to operate fast and efficiently. These enzymes have inspired the development of molecular catalysts, which have dramatically improved in efficiency in recent years, to the point that some synthetic catalysts even outperform hydrogenases under certain conditions. In this work, we use a reversible noble-metal-free homogeneous catalyst, the [Ni(PCy2NPhe2)2]2+ complex, and we covalently immobilize it on a functionalized highly oriented pyrolytic graphite “edge” (HOPGe) electrode surface. This catalyst is not water soluble, but once it is surface-confined on the electrode, it maintains its catalytic properties in aqueous solutions, showing reversibility for H2 oxidation/reduction. Immobilization of the [Ni(PCy2NPhe2)2]2+ complex onto a multi-walled carbon nanotubes coated electrode leads to even higher catalytic current densities and enhanced stability.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1347874
• Report Number(s): PNNL-SA-119142; KC0302010
• Journal Information: Electroanalysis, Journal Name: Electroanalysis Journal Issue: 10 Vol. 28; ISSN 1040-0397
• Publisher: Wiley
• Country of Publication: United States
• Language: English

Related Subjects

Bio-inspired catalyst
electrocatalysis
hydrogen production/oxidation
modified electrodes
noble-metal-free catalysis