Hydrogenase enzymes: Application in biofuel cells and inspiration for the design of noble-metal free catalysts for H2 oxidation

Biohydrogen for a New Generation of H2/O2 Biofuel Cells: A Sustainable Energy Perspective

“…As an illustration, Hases have been the subject of five recent reviews, one of them covering most of the issues that are currently investigated. [20,28,[76][77][78] In the present review we will focus especially on Hases that are able to oxidize H 2 in the presence of O 2 , which are enzymes that are fundamentally more suitable for EBFC development.…”

“…Some of them are promising for H 2 oxidation, among which the Ni bisdiphosphane complex displays a notable activity in organic solvents. [19,20] An analogue to Dubois' complexes was even grafted on carbon nanotube (CNT) networks and shown to be efficient for H 2 oxidation in aqueous acidic solution, displaying good stability and no CO poisoning. [21,22] More recently, a very elegant and promising combination of a protein scaffold and active site synthetic analogue demonstrated the possibility of artificial maturation of hydrogenases (Hases), opening a new avenue toward synthetic biological hydrogen catalysts.…”

A simple method for the preparation of bio-inspired nickel bisdiphosphine hydrogen-evolving catalysts

“…Additionally, in the course of this study, we identified that chloride anions can bind to the nickel center in nickel bisdiphosphine complexes, which significantly affects their electrochemical behavior and strongly diminishes their catalytic activity for hydrogen evolution. (2) in good yields. These complexes show 1 H and 31 P NMR spectra similar to those of the complex synthesized from the hexakisacetonitrilenickel(II) precursor as prepared in our laboratory and previously reported by DuBois and coworkers [12].…”

“…This rare and expensive metal is not itself a renewable resource, so the viability of a hydrogen economy depends on the design of new efficient and robust electrocatalytic materials based on Earth-abundant elements. A competitive alternative to platinum could be found in living micro-organisms that metabolize hydrogen using hydrogenases [1,2]. Catalysis in hydrogenases requires only base-metal centers (nickel and iron), and the structures of their active sites have inspired the design of new synthetic catalysts based on these metals [3][4][5][6][7][8], cobalt [8,9], or other Earth-abundant elements such as molybdenum [10] and manganese [11].…”

“…Immobilization of such synthetic catalysts on multiwall carbon nanotubes (CNTs), either covalently or through p-p stacking interactions, has yielded catalytic nanomaterials that when interfaced with a Nafion membrane show bidirectional and reversible catalytic activity for hydrogen evolution and oxidation at the thermodynamic equilibrium, prolonged stability under turnover conditions, and resistance to CO poisoning [2,18,19]. However, the reported preparation of such nickel bisdiphosphine compounds requires the use of anhydrous nickel salts in the form of the hexakisacetonitrilenickel(II) complex, which must be synthesized by the oxidation of metallic nickel by nitrosonium cations in acetonitrile.…”