Prediction of chromatographic retention of metal complexes from stability constants measured by ion chromatography

Incorporating three-dimensional ordered macropores into high-entropy oxides for catalytic soot combustion

“…The higher Ni content was attributed to a more stable coordination interaction between Ni 2+ and citric acid (the stability constants of metal ions with citric acid were 3.71 for Ni 2+ , 3.55 for Co 2+ , and 2.65 for Mn 2+ ). 44–47…”

“…42,43 Combined with the Gibbs free energy formula (DG = DH − TDS), the enhanced entropy would contribute to the decrease of Gibbs free energy, thus favoring the stability of the cubic crystal system. And the lower concentration of Ce might be attributed to the weaker complex interaction with citric acid than transition metals like Ni and Co. [44][45][46][47] For example, Constantine et al found a lower extraction rate of Ce 2+ than Ni 2+ and Co 2+ at the same conditions with citric acid complexation (88.84% for Ce 2+ , 90.70% for Ni 2+ , and 91.62% for Co 2+ ). 44 For 3DOM-HEO-ZrO x , the molar ratio was 53 : 10 : 10 : 8 : 10 : 9 for Zr : Ni : Fe : Cu : Mn : Co.…”

“…The higher Ni content was attributed to a more stable coordination interaction between Ni 2+ and citric acid (the stability constants of metal ions with citric acid were 3.71 for Ni 2+ , 3.55 for Co 2+ , and 2.65 for Mn 2+ ). [44][45][46][47] To demonstrate the dispersion of doped elements in the parent oxide, those HEOs were further characterized by highangle annular dark-eld scanning transmission electron microscopy (HAADF-STEM) and energy dispersive spectroscopy (EDS) mapping technologies. As shown in Fig.…”