DESENVOLVIMENTO DE UM ELÉTRODO COSTEFFECTIVE EM AÇO NÍQUEL PARA APLICAÇÃO NUM ELETROLISADOR ALCALINO

André Filipe Granadeiro Martins

Key information

Authors:

André Filipe Granadeiro Martins (André Filipe Granadeiro Martins)

Supervisors:

Ricardo Nascimento; Diogo Miguel Franco dos Santos (Diogo M. F. Santos)

Published in

11/25/2022

Abstract

Hydrogen is considered as one of the alternatives to achieve carbon neutrality by 2050. Water electrolysis through renewable energy is currently the method with the fewest emissions to produce hydrogen. Alkaline electrolysis (AWE) is one of the most promising technologies, however, it is essential to increase the efficiency of hydrogen production. This work is included in the H2Czero project developed by ISPT - Industrial Services, S.A., with the objective of developing a low-cost AWE with high efficiency. Seven substrates were compared, such as 304 stainless steel (SS), 316 SS and nickel alloy in relation to hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The dynamic hydrogen bubble template (DHBT) mechanism was studied on different substrates and varying the deposition time, on 316 SS. The morphology of the electrodes obtained was analyzed using scanning electron microscopy, where porous structures were found. In 8M KOH, at room temperature, voltammetric cycles and linear sweeps voltammetric studies were performed to obtain the catalytic activity. It was possible to reach an overvoltage of 87 mV for the current density of 10 mAcm-2, for HER, with a 316 SS substrates porous electrode, via DHBT electrodeposition. For OER, with DHBT on 304 SS, an electrode with an overvoltage of 226mV for 10mAcm-2 was obtained. The results allowed to validate the DHBT on mesh substrates, for future use in a low-cost and highly efficient AWE.