A team led by Genki Kobayashi at the RIKEN Pioneering Research Institute in Japan announced it has developed a mechanochemical process that nearly doubles the hydrogen-storage capacity of perovskite crystalline powders, a breakthrough with direct implications for ammonia synthesis and hydrogen economy applications. The findings were reported in the Journal of the American Chemical Society.
The research addresses a longstanding challenge: conventional high-temperature or high-pressure methods replace only about 17% of oxygen ions in perovskite powders with hydride ions, limiting hydrogen storage potential. By physically grinding and mixing compounds at room temperature, the researchers achieved a 34% replacement rate, effectively maximizing hydrogen saturation in barium titanate oxyhydride.
Tests showed that mechanochemically produced powders not only stored more hydrogen but also performed better as catalysts for ammonia production compared to materials synthesized with heat. Analysis revealed that the grinding process induced lattice deformations that enhanced catalytic activity.
According to the researchers, the results provide design guidelines for functional materials that incorporate hydride ions. While 34% is likely the upper storage limit for barium titanate, the team expects other perovskite materials may achieve even higher capacities. Kobayashi said the mechanochemical approach could ultimately support advances in ammonia synthesis and electrochemical devices such as fuel cells.
