Advances and prospects in manufacturing of ceramic oxygen and hydrogen separation membranes

Hydrogen and oxygen are considered essential gases for industrial processes. Hydrogen is the main candidate to store discontinuous electricity produced by renewable energy sources playing a crucial role in achieving the European Green Deal goals. Ceramic membranes can supply theoretically 100 % pure gases and can be directly applied to high-temperature plants (500–900 ◦C). This technology shows reduced production costs, higher chemical and thermal stability compared to the precious metal-based counterparts. Despite the recent progress, challenges linked to its production processes and performances for industrial applications remain to be addressed. This review aims to give a comprehensive overview of the most used techniques and new approaches regarding the manufacturing of the most performing asymmetric (porous-dense) ceramic membranes. Oxygen separation technology is based on well-established performing materials; tangible progress is expected consid ering a fine-tuning of the membrane microstructure and architecture. Hydrogen separation membranes show a lower degree of advancement than the oxygen ones, suggesting the need for new materials design. For both types of membranes, one of the key requirements for industrial applications remains the manufacturing process optimization to achieve increased gas permeability and reliable components on a mass-production scale. This review offers a critical vision of the membrane technology, emphasizing the opportunities and challenges of each manufacturing method and structure. New prospects and frontier of shaping for this technology are addressed.