Rhodium dihydride (RhH(2)) with high volumetric hydrogen density
2011 (English)In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 108, no 46, 18618-18621 p.Article in journal (Refereed) Published
Materials with very high hydrogen density have attracted considerable interest due to a range of motivations, including the search for chemically precompressed metallic hydrogen and hydrogen storage applications. Using high-pressure synchrotron X-ray diffraction technique and theoretical calculations, we have discovered a new rhodium dihydride (RhH(2)) with high volumetric hydrogen density (163.7 g/L). Compressing rhodium in fluid hydrogen at ambient temperature, the fcc rhodium metal absorbs hydrogen and expands unit-cell volume by two discrete steps to form NaCl-typed fcc rhodium monohydride at 4 GPa and fluorite-typed fcc RhH(2) at 8 GPa. RhH(2) is the first dihydride discovered in the platinum group metals under high pressure. Our low-temperature experiments show that RhH(2) is recoverable after releasing pressure cryogenically to 1 bar and is capable of retaining hydrogen up to 150 K for minutes and 77 K for an indefinite length of time.
Place, publisher, year, edition, pages
2011. Vol. 108, no 46, 18618-18621 p.
metal hydrides, phase transition
IdentifiersURN: urn:nbn:se:uu:diva-163663DOI: 10.1073/pnas.1114680108ISI: 000297008900021OAI: oai:DiVA.org:uu-163663DiVA: diva2:464954