polyvalentcationcontaining

Polyvalentcationcontaining is a descriptive term used in chemistry and materials science to refer to chemical species or materials that incorporate polyvalent cations—cations with valence greater than one—in their composition or structure. Polyvalent cations include, for example, Ca2+, Fe3+, Al3+, Ti4+, and Zr4+. The term covers discrete compounds, polymers, and extended solids in which these multivalent ions serve as network formers or cross-linkers.

Examples include layered double hydroxides with divalent and trivalent metal ions, aluminates, ferrites, and many coordination polymers in which metals such as Al3+ or Fe3+ coordinate to ligands. In polymers or gels, multivalent cations can cross-link portionally, producing enhanced stiffness or altered swelling behavior.

Significance: multivalent cations increase charge density, promote cross-linking, and influence stability, crystallinity, and electrostatic interactions. This affects catalytic activity, ion selectivity, and mechanical properties. In energy storage and conversion, polyvalent cations are central to certain battery chemistries (e.g., Mg2+- or Al3+-based systems) and to catalysts and supercapacitors.

Synthesis and characterization: methods include co-precipitation, hydrothermal or solvothermal synthesis, ion exchange, or templating. Characterization typically involves X-ray diffraction, electron microscopy, spectroscopy, and elemental analysis to confirm composition and oxidation state.

Note: The term is descriptive rather than a formal classification; it is used when the presence of polyvalent cations is a defining feature of the material or compound.