Green hydrogen makes it possible to replace coal, oil, and natural gas in areas where electrification is not possible or is difficult to achieve, such as in the chemical industry, steel production, and shipping or aviation. These sectors account for 20–30% of global CO2 emissions, and correspondingly large quantities of green hydrogen are needed to make these sectors sustainable. Currently, green hydrogen is produced almost exclusively through electrolysis using green electricity. However, hydrogen production competes directly with other uses of green electricity (grid injection, e-mobility, heat pumps, etc.), which currently enable greater CO₂ savings than the production and use of green hydrogen.
Against this backdrop, the presentation explores an alternative approach: the direct conversion of sunlight and water into hydrogen via photocatalysis. This process requires no electricity and thus avoids the competition for green electricity. The presentation provides insights into ongoing research in this field, which focuses on the following questions: Which materials (so-called photocatalysts) enable the efficient conversion of sunlight and water into hydrogen, and how can we produce and improve them? What types of reactors and facilities are needed to implement this process on a large scale? At what point does this hydrogen production route become competitive, and how energy- and resource-efficient is the process?
