Experimental Determination and Computational Prediction of Androstenedione Solubility in Alcohol + Water Mixtures

This article evaluates the accuracy and applicability of three of the most common solubility models (i.e., Jouyban–Acree, NRTL-SAC, and COSMO-RS) in prediction of androstenedione (AD) solubility in binary mixtures of methanol + water and ethanol + water. The solubilities were measured from (275 to 325) K using medium-throughput experiments and then well represented mathematically by modified Apelblat and CNIBS/Redlich–Kister equations. The computational results show that AD solubility decreases monotonically with increasing water concentration in methanol + water mixtures, but it has a maximum at 0.15–0.30 mole fraction of water in the ethanol aqueous solution. Moreover, the performance of three solubility prediction models in this particular case was compared to identify the advantages and disadvantages of each model. The overall average relative deviation (ARD) for solubility prediction is 4.4% using Jouyban–Acree model, while it is 18.3% with NRTL-SAC model. Surprisingly, COSMO-RS model in combination with reference solubility achieves a good performance for solubility prediction in mixed solvents, including the prediction of synergistic effect of solvents, with overall ARD of only 4.9%

Nature of Catalytic Behavior of Cobalt Oxides for CO₂ Hydrogenation

Cobalt oxide (CoOx) catalysts are widely applied in CO2 hydrogenation but suffer from structural evolution during the reaction. This paper describes the complicated structure–performance relationship under reaction conditions. An iterative approach was employed to simulate the reduction process with the help of neural network potential-accelerated molecular dynamics. Based on the reduced models of catalysts, a combined theoretical and experimental study has discovered that CoO(111) provides active sites to break C–O bonds for CH4 production. The analysis of the reaction mechanism indicated that the C–O bond scission of *CH2O species plays a key role in producing CH4. The nature of dissociating C–O bonds is attributed to the stabilization of *O atoms after C–O bond cleavage and the weakening of C–O bond strength by surface-transferred electrons. This work may offer a paradigm to explore the origin of performance over metal oxides in heterogeneous catalysis