Proton Conducting Ceramics for Hydrogen Extraction

In recent years, the green hydrogen economy has become a rapidly growing field, and the sustainable production of hydrogen for transport and industrial applications is gaining ever-growing attention. Although state-of-the-art hydrogen production via hydrocarbon steam reforming is efficient, it is also an energy-intensive process that produces large amounts of CO₂ emissions.

An emerging, more sustainable alternative to traditional hydrogen production is proton-conducting ceramic cells (PCCCs), which can function as gas separation membranes. In PCCCs, hydrogen is produced by in-situ steam reforming of a carbon-based fuel on one side of the membrane. From this hydrogen-rich gas, the hydrogen is electrochemically pumped through the proton-permeable electrolyte, and high-purity hydrogen is obtained on the other side of the membrane.

If successfully upscaled, this technology could be a breakthrough for onboard hydrogen generation for mobile applications since it can generate high-purity hydrogen in one unit and a single step. The produced hydrogen could then be directly used in a Proton Exchange Membrane Fuel Cell (PEMFC) stack for power generation, for example.

The present work is dedicated to developing and upscaling stacks consisting of planar symmetrical PCCCs. Particular focus was paid to the sealing and design, which accommodates the symmetrical electrodes of the PCCCs and ensures safe operation by preventing gas mixture and leakage, which would lead to the failure of the stack.

A new glass-ceramic sealant compatible with the other stack components was developed successfully and tested. In parallel different stack designs considering easy manufacturing and assembling were designed. As final proof-of-concept, the most promising design was selected and successfully assembled and realized.