Resolving the stability and structure of strontium chloride amines from equilibrium pressures, XRD and DFT

摘要: Abstract Strontium chloride octamine, Sr(NH3)8Cl2, has been shown to be a highly efficient ammonia reservoir for selective catalytic reduction of NOx gases in vehicle exhaust and hold great potential indirect hydrogen storage. The possible applications such metal amines depend explicitly on the conditions release it is thus essential understand exact ab- desorption mechanisms. Here, we apply equilibrium pressure measurements from desorption, X-ray powder diffraction density functional theory calculations identify thermodynamically stable Sr(NH3)Cl2, Sr(NH3)2Cl2 Sr(NH3)8Cl2 phases. crystal structures were solved space groups Cmcm, Aem2 Pnma respectively. Controversy regarding existence diamine phase resolved basis combined structural thermodynamic analysis mechanisms, yielding structure with nearly same stability as monoamine. Depending temperature pressure, found have marginally higher or lower than monoamine which explains why some experiments not others.