Investigation of Pore Size on the Hydrogen Evolution Reaction of 316L Stainless Steel Porous Electrodes

This work aims to analyze the effect of pore size on the catalytic reaction of 316L stainless steel electrodes. Porous compacts were fabricated using the space holder technique and sintering at low temperatures. The fabricated porous compacts were characterized using computed tomography and the hydrogen evolution reaction was evaluated under 0.5 M and 1.5 M NaOH. Results indicate that porosity is well controlled by the pore formers, which allows different pore size distributions of pores with similar relative density values to be obtained. The pores are fully interconnected, allowing the passing of fluid throughout the compacts. Permeability is sensitive to the pore size, increasing as the pore size does. The catalytic activity of hydrogen evolution reaction HER is improved as the pore volume and pore size increase concerning the compact fabricated without pore formers. The compact that showed higher Cdl and Rf values was fabricated with S100 pore formers, which means a higher active area that favors the HER. It can be concluded that porosity enhances HER reactivity. However, larger pores are not beneficial due to a more significant permeability value.