New insights into the role of solution additive anions in Mg2+ dehydration: implications for mineral carbonation

Abstract

Simulations of hydrated Mg²⁺, in the absence and presence of several solution additive anions, show that in pure liquid water Mg(H₂O)₆²⁺ is the only stable coordination state; yet anions may stabilise undercoordinated five-hydration configurations. Solution composition can lower the barrier to Mg²⁺ dehydration and subsequent incorporation into the lattice of Mg-carbonates, promoting low-temperature crystallisation.