Dehydrogenation Properties of Magnesium Hydride Loaded with Fe, Fe−C, and Fe−Mg Additives. Issue 3 (30th December 2016)

• Record Type: Journal Article
• Authors: Pukazhselvan, D.; Nasani, Narendar; Yang, Tao; Bdikin, Igor; Kovalevsky, Andrei V.; Fagg, Duncan P.
• Is Part Of: Chemphyschem. Volume 18:Issue 3(2017)
• Page Start: 287
• Page End: 291
• Publication Date: 2016-12-30
• Subjects: catalysis -- dehydrogenation -- Fe-carbon composites -- magnesium hydride -- X-ray diffraction; Chemistry, Physical and theoretical -- Periodicals; 541.05
• DOI: 10.1002/cphc.201601078
• Languages: English
• ISSNs: 1439-4235

Abstract

Abstract: This study highlights that Fe additives offer better catalytic properties than carbon, Fe−C (iron carbide/carbon composites), and Fe‐Mg (Mg2 FeH6 ) additives for the low‐temperature dehydrogenation of magnesium hydride. The in situ X‐ray diffraction measurements prove the formation of a Mg2 FeH6 phase in iron additive loaded MgH2 . Nonetheless, differential scanning calorimetry data suggest that this Mg2 FeH6 phase does not have any influence on dehydrogenation properties of MgH2 . On the other hand, the composite system Mg2 FeH6 /MgH2 shows significantly improved dehydrogenation properties even in absence of further additives. It is suggested that the improved system performance of Fe loaded MgH2 is attributed to restrictions on crystal growth of MgH2 and the catalytic behavior of Fe nanoparticles, rather than any intrinsic catalytic properties offered by the formed mixed metal phase Mg2 FeH6 . Abstract : Active or not : Although in situ XRD measurements suggest the formation of a Mg2 FeH6 metastable phase during the dehydrogenation of Fe loaded MgH2, further investigation suggest that Mg2 FeH6 does not present any catalytic influence for the system. This is evident from the observation that dehydrogenation of Mg2 FeH6 ‐loaded MgH2 occurs at considerably higher temperatures compared to Fe loaded MgH2 .