Birmingham Catalyst Splits Water Into Hydrogen at 500°C Lower Temperatures, Promising Cheaper Fuel From Waste Heat
A University of Birmingham team reports a barium-niobium-calcium-iron perovskite that thermochemically splits water at 150-500°C and regenerates 500°C below current catalysts.
Overview
Researchers at the University of Birmingham have developed a perovskite-based catalyst that splits water into hydrogen at much lower temperatures than existing thermochemical approaches, according to the University of Birmingham. The material produces hydrogen at temperatures between 150 and 500°C and regenerates between cycles at 700 to 1,000°C — roughly 500°C lower than current methods, ScienceDaily reported.
The work, led by Professor Yulong Ding of the University’s School of Chemical Engineering, was published in the International Journal of Hydrogen Energy, according to the University of Birmingham.
What We Know
Thermochemical water splitting uses a catalyst to separate water into hydrogen and oxygen, according to ScienceDaily. The barrier to date has been heat: existing catalysts split water at 700 to 1,000°C and must be regenerated between cycles at 1,300 to 1,500°C, according to the University of Birmingham. The Birmingham catalyst lowers both stages, producing hydrogen at 150 to 500°C and regenerating at 700 to 1,000°C, Interesting Engineering reported.
The team calls the material a BNCF perovskite, made from barium, niobium, calcium and iron, with the best-performing formulation designated BNCF100, according to the University of Birmingham. The full composition is described in the paper as Ba2Ca0.66Nb1.34-xFexO6-δ, published under the title “Remarkable thermochemical water-splitting on Ba2Ca0.66Nb1.34-xFexO6-δ perovskites at medium temperatures for hydrogen production” (International Journal of Hydrogen Energy). The study confirmed the catalyst retained its ability to produce hydrogen over 10 cycles, according to the University of Birmingham.
A provisional cost analysis found that water splitting with the perovskite catalyst can deliver hydrogen at a lower cost than either green hydrogen, produced from water by electrolysis, or blue hydrogen, produced from methane with carbon capture and storage, according to the University of Birmingham. The advantage is greatest in regions with inexpensive renewable electricity, such as Australia, ScienceDaily reported.
The lower operating temperature is what makes the approach attractive for siting near energy sources. “The lower overall temperature of the process could enable hydrogen to be produced nearby renewable energy generation plants,” Professor Ding said, according to the University of Birmingham. Ding also noted that waste heat from industry could be “harnessed as the heat input for low-temperature hydrogen production,” TechXplore reported.
The research was conducted in collaboration with the University of Science and Technology Beijing, with co-authors Biduan Chen, Wenyi Huang, Wei Guo, Lige Tong and Li Wang, according to ScienceDaily. University of Birmingham Enterprise has filed a patent application covering the use of BNCF catalysts for splitting water at low temperatures, according to the University of Birmingham.
Why It Matters
Most hydrogen today is made from fossil fuels. Approximately 95% of current production relies on fossil fuels, steam methane reforming accounts for nearly half of the global supply, and electrolysis provides only 4% of the supply, Interesting Engineering reported. A water-splitting route that runs on moderate heat rather than electricity or methane could open a different path to low-carbon hydrogen, particularly where high-temperature industrial waste heat is already available.
What We Don’t Know
The cost analysis is described as provisional, and the cycling demonstration covered 10 cycles rather than the thousands required for commercial durability, according to the University of Birmingham. The university is seeking development partners to advance the approach, and no production-scale timeline, yield figures, or independent cost validation have been published. Whether BNCF perovskites can scale from a laboratory result to an industrial process remains unproven.