Van Marum colloquium by prof. Germano Tremiliosi-Filho from the University of São Paulo.

Development of materials for hydrogen production via ethanol reform
Molecular hydrogen is a part of the electrical mobility and represent one of the key solution for the decarbonization of the transport sector. Ethanol reform is a friendly source of hydrogen that function at relatively low temperatures (25 °C – 85 °C) and is represented by the following reactions:

Anodic reaction:         C2H5OH + 3H2O → 2CO2 + 12H+ + 12e-   (1)

Cathodic reaction:      12H+ + 12e- → 6H2   (2)

Overall reaction:         C2H5OH + 3H2O → 2CO2 + 6H2   (3)

The overall reaction (3) is similar to a steam reforming process (usually operating at high temperatures: 600 °C – 800 °C). The energetic demanded to produce 1 mol of hydrogen is + 58 kJ/mol, with a cell voltage at 0.084V, that it is much smaller than that from water electrolysis decomposition, + 286 kJ/mol with a cell voltage at 1.23 V, leading to a lower electric consumption. However, the relatively slow kinetics limitations of reactions (1) and (2) leads to high-cell voltage, ca. 0.6 – 0.8 V, for the electrolysis ethanol cell operating at 1 A cm-2. Thus, the high efficiency of the electrochemical reforming of ethanol demands the use of excellent catalysts for the anodic and for the cathodic reactions. Thus, in this talk will be presented the development of nanostructured materials reasoned in the systems: Mo/S and Ni/Fe, in order to assembly efficient ethanol electrolysis cell.

The "Van Marum Colloquia" is a collaborative lecture series between the LION and LIC institutes, focusing on fundamental and applied surface science.