Porous Transport Layers for Proton Exchange Membrane Electrolysis Under Extreme Conditions of Current Density, Temperature, and Pressure

Abstract

Hydrogen produced via water electrolysis powered by renewable electricity or green H2 offers new decarbonization pathways. Proton exchange membrane water electrolysis (PEMWE) is a promising technology although the current density, temperature, and H2 pressure of the PEMWE will have to be increased substantially to curtail the cost of green H2. Here, a porous transport layer for PEMWE is reported, that enables operation at up to 6 A cm−2, 90 °C, and 90 bar H2 output pressure. It consists of a Ti porous sintered layer (PSL) on a low‐cost Ti mesh (PSL/mesh‐PTL) by diffusion bonding. This novel approach does not require a flow field in the bipolar plate. When using the mesh‐PTL without PSL, the cell potential increases significantly due to mass transport losses reaching ca. 2.5 V at 2 A cm−2 and 90 °C. On the other hand, the PEMWE with the PSL/mesh‐PTL has the same cell potential but at 6 A cm−2, thus increasing substantially the operation range of the electrolyzer. Extensive physical characterization and pore network simulation demonstrate that the PSL/mesh‐PTL leads to efficient gas/water management in the PEMWE. Finally, the PSL/mesh‐PTL is validated in an industrial size PEMWE in a container operating at 90 bar H2 output pressure.

On the Durability of Iridium‐Based Electrocatalysts toward the Oxygen Evolution Reaction under Acid Environment

“…Moreover, while most studies are conducted at room temperature, the operation temperature of PEMWEs is usually 60-80 °C. [105] The agglomeration of nanostructured active species would play a more significant role in the deactivation of OER electrocatalysts at higher temperatures, and the dissolution kinetics of Ir species would probably be enhanced. Therefore, the durability of OER electrocatalysts at high temperatures should be taken into account.…”

Cerium-Doped Nickel Phosphide Nanosheet Arrays as Highly Efficient Electrocatalysts for the Hydrogen Evolution Reaction in Acidic and Alkaline Conditions

“…Prominently, the overpotential required for Ce 0.10 -Ni 2 P@NF in order to reach the current density of 200 mA cm –2 is 194 mV, which is slightly higher than that of Pt/C (192 mV, respectively) (Figure S5). The overpotentials of Ce 0.10 -Ni 2 P@NF are lower than those of the Pt/C catalyst when the current density is larger than 204 mA cm –2 (Figure a), suggesting its better catalytic HER activity than the Pt/C catalysts in a commercial alkaline water electrolyzer with a load of about 0.5 A cm –2 . Tafel curves can be used to evaluate the HER kinetics of the as-prepared electrocatalysts. ,, The Tafel slope fitted from the polarization curve by the Tafel equation (η = b log j + a , where a and b are constants) is shown in Figure b.…”

Assessing potential profiles in water electrolysers to minimise titanium use

“…The use of a microporous layer at the PTL/CL interface has been studied by various groups with the results broadly indicating that, notwithstanding material substitution advantages as considered in this paper, such a layer improves both the mass transport and electrode kinetics. [34][35][36][37][38][39] Such a scheme may therefore have benefit both through enabling the use of cheaper materials and in improving performance.…”