Materials for low cost, scalable, thermochemical hydrogen production

Engineers in Prof. Arunava Majumdar's laboratory have formulated high-entropy phase-change materials that can split water to produce hydrogen at moderate temperatures using a scalable, carbon-free process. The hydrogen is produced through a two-step solar-powered thermochemical redox reaction. Then it can be harnessed to reduce carbon dioxide and produce chemicals such as plastics, syngas or transportation fuel.

The reaction is compatible with the existing infrastructure of the chemical industry reaction because it proceeds at moderate temperatures (~1200^oC or lower) with extremely fast oxygen release kinetics. In addition, the materials used for the reaction are in powder form, allowing the process to be scaled volumetrically in well-known chemical reactor designs (e.g. fluidized bed). This water-splitting technology is designed to potentially produce carbon-free hydrogen at prices competitive with steam methane reforming (SMR). Furthermore, it may turn CO₂ from an environmental liability to an asset by converting it CO feedstock for chemical and renewable fuel production.

Schematic diagram of two-step thermochemical water splitting reactions using the proposed high-entropy mixed oxides.

Stage of Research
The inventors have formulated the entropy stabilized material, verified that it can produce hydrogen at 1200^oC or lower (lower temperature than current state of the art), and performed repeatability studies to ensure that it can be cycled continuously to produce hydrogen.