PhD - Leuven | More than two weeks ago
The realization of Megawatt production of pressurized hydrogen gas from renewable electricity is currently limited to two commercially available technology options: alkaline WE (AWE) and proton-exchange-membrane (PEM) electrolysis. The alkaline technology is the most mature and can deliver stacks ranging from a few kW to 10 MW (H2 production volumes of 1-2000 Nm³/h per stack) thanks to electrodes and membranes integrated in stacks with a few square meters of active area per cell. The PEM technology is a much younger technology that still has to prove itself in the field in terms of reliability and maintenance but has single stack electrolyzers of few 200 Nm³/h already due to the higher current density it can deliver. Unfortunately, PEM technology relies on rare noble metal electrocatalysts for both the anode and cathode, which is not sustainable for gigawatt deployment of green hydrogen, in general. Hence, unfortunately, both existing electrolyzer technologies still pose critical issues towards cost of hydrogen for offshore green hydrogen. Our proposed solution is to combine the best of both worlds by the development of a gas impermeable alkaline or hydroxyl exchange membrane (HEM) technology, which combined with a novel high surface-area catalytic nanomesh (NM) material will exceed PEM in performance while being free of noble metals as for the AWE. Both polymer (AEW) and inorganic membranes are under development. These new HEM will allow lower alkaline chemistries and eventually even water as for PEM technology. However, new electrocatalyst are needed for this low alkaline chemistry. At imec, we have developed a few µm thin NM material which combines high-surface area and high porosity while it is mechanically robust due to the regular spacing of the interconnected wires (https://www.imec-int.com/en/articles/novel-nanomaterial-promises-improvements-in-batteries-and-many-more-sustainable-applications). It was shown that a Ni-NM of about 5 µm thick outperformed the 300 times thicker state-of-the-art nickel foam electrodes with a factor 10-20 in current density due to the higher effective surface area and improved mass transport through this ultra-thin electrode. In this PhD project, you will develop new catalytic approaches combined with the nanomesh. You will explore surface-limited electrodeposition processes for ultra-thin catalyst coatings and evaluate novel compounds and alloys for hydrogen evolution (cathode) and oxygen evolution (anode) reactions in low alkaline environments.
Required background: Chemistry, materials science, nanotechnology
Type of work: 100% experimental
Supervisor: Philippe Vereecken
Daily advisor: Siggi Wodarz
The reference code for this position is 2021-081. Mention this reference code on your application form.