An ammonia sponge

Abstract

A long-overlooked metal-organic framework (MOF) acts as a sponge for ammonia, selectively soaking up and releasing the corrosive gas at moderate pressures and temperatures of up to 175 °C. Using the material to separate ammonia from a mix of nitrogen and hydrogen could make ammonia synthesis less energy intensive, which could change how and where ammonia-based fertilizers and shipping fuels are made. Researchers in Jeffrey R. Long’s lab at the University of California, Berkeley, discovered the ammonia-adsorbing properties of the MOF, which is made of copper and trans -1,4-cyclohexanedicarboxylate ( Nature 2023, DOI: 10.1038/s41586-022-05409-2 ). MOF chemists had largely overlooked this material and others like it because at first glance their structures aren’t particularly interesting, says Benjamin E. R. Snyder, the report’s first author. Snyder, who did a postdoctoral fellowship in Long’s lab, recently started his own lab at the University of Illinois Urbana-Champaign. “Once you approach them with the