Unique thermodynamic relationships for Δf H o and Δf G o for crystalline inorganic salts. I. Predicting the possible existence and synthesis of Na2SO2 and Na2SeO2

Mechanism of synergistic removal of NO and SO2 by sodium bicarbonate

Sodium bicarbonate (NaHCO3) is considered to be an effective alkaline adsorbent for SO2 removal and surprisingly, the concentration of NO is significantly reduced along with the generation of NO2 during its desulfurization. Unfortunately, the mechanism of NO interaction with NaHCO3, SO2 and O2 is ambiguous. In this work, the effects of absorption gas and absorber composition on SO2/NO absorption performance were explored, the absorption products were characterized using XPS and SEM, and the Gibbs free energy of the inferred reaction path was calculated based on density functional theory (DFT). The results showed that SO2 and O2 synergistically promoted the absorption and removal of NO by NaHCO3, which could completely remove SO2 and absorb 90% of NO at 160 °C. Sodium metabisulfite (Na2S2O5) and sodium dithionate (Na2S2O6) were identified as the active substances responsible for efficient NO absorption, and the oxidation of Na2S2O5 to Na2S2O6 is the controlling step of the NO removal reaction. Specifically, Na2S2O5 is an intermediate produced by the reaction of NaHCO3 with SO2, and subsequently reacts with O2 to produce Na2S2O6, which releases reactive oxygen species to oxidize NO to NO2. In addition, when the S/N ratio is greater than 1 and the O2 content is greater than 5%, both SO2 and NO can maintain removal efficiency higher than 90%, indicating that the absorption reaction of SO2 and NO by NaHCO3 is highly adaptable to the flue gas composition.

Controlling Residual Lithium in High-Nickel (>90 %) Lithium Layered Oxides for Cathodes in Lithium-Ion Batteries

The rampant generation of lithium hydroxide and carbonate impurities, commonly known as residual lithium, is a practical obstacle to the mass-scale synthesis and handling of high-nickel (>90 %) layered oxides and their use as high-energy-density cathodes for lithium-ion batteries. Herein, we suggest a simple in situ method to control the residual lithium chemistry of a high-nickel lithium layered oxide, Li(Ni_0.91 Co_0.06 Mn_0.03 )O₂ (NCM9163), with minimal side effects. Based on thermodynamic considerations of the preferred reactions, we systematically designed a synthesis process that preemptively converts residual Li₂ O (the origin of LiOH and Li₂ CO₃ ) into a more stable compound by injecting reactive SO₂ gas. The preformed lithium sulfate thin film significantly suppresses the generation of LiOH and Li₂ CO₃ during both synthesis and storage, thereby mitigating slurry gelation and gas evolution and improving the cycle stability.

Absolute ion hydration enthalpies and the role of volume within hydration thermodynamics

This paper reports that various thermodynamic properties in aqueous media for certain individual ions and for compounds are linear functions of the inverse cube root of the solid respective ionic and compound solid state volumes, V_m^−1/3.

Unique thermodynamic relationships for ΔfHo and ΔfGo for crystalline inorganic salts. I. Predicting the possible existence and synthesis of Na2SO2 and Na2SeO2. Addendum

Addendum to Vegas et al. [(2012), Acta Cryst. B68, 511-527].

Predictive thermodynamics for ionic solids and liquids

Thermodynamic properties of ionic solids and liquids may reliably be predicted using volume-based thermodynamics (VBT) and thermodynamic difference rules (TDR).