Hydrogenase mimic  A hydrogenase mimic or bio-mimetic is an enzyme mimic of hydrogenases. One of the more interesting applications of hydrogenases is to produce hydrogen, due its capacity to catalyze its redox reaction:  2H+ + 2e- ----> H2  In the field of hydrogen production, the incorporation of chemical compounds in electrochemical devices to produce molecular hydrogen has been a topic of huge interest in the recent years due to the possibility of using hydrogen as a replacement of the fossil fuels as an energetic carrier. This approach of using materials inspired by natural models to do the same function as their natural counterparts is called bio-mimetic approach. Nowadays this approach has received a big impulse due to the availability of high-resolution crystal structures of several hydrogenases obtained with different techniques. The technical details of these hydrogenases are stored in electronic databases at disposition to who may be interested. This information has allowed to determine the important parts of the enzyme necessary to catalyze the reaction and determine the pathway of the reaction in a very detailed way. Which allow to have a very good comprehension of what is necessary to catalyze the same reaction using artificial components. Several studies have demonstrated the possibility to develop chemical cells inspired by biological models to produce molecular hydrogen, for example: Selvaggi "et al." explored the possibility to use energy captured by the PSII, developing for that goal, an organic-inorganic hybrid system replacing the PSII protein complex by microspheres of TiO2 a photo-inducible compound. In order to get the hydrogen production, the TiO2 microspheres were covered with hydrogenases extracted from the marine thermophile "Pyrococcus furiosus", in that way the energy of the light was captured by the TiO2 microspheres and used to generate protons and electrons from water with the subsequent production of 29 µmol de H2 hour−1. The obtained results from immobilization of hydrogenases on the surface of electrodes have demonstrated the viability of incorporating these enzymes in electrochemical cells, due to their ability to produce gaseous hydrogen through a redox reaction. (Hallenbeck and Benemann). This opens the possibility of using biomimetic compounds in electrodes to generate hydrogen. Until the present day several bio-mimetic compounds have been developed: Collman "et al." produced rutherium porphyrins, furthermore of the bio-mimetic compounds published by the research teams of Rauchfuss, Darensbourg and Pickett (in Artero and Fontecave) who developed bio-mimetic compounds of the [Fe] hydrogenase.