Oxidative Fluorination of Cu/ZnO Methanol Catalysts

Methanol Synthesis by Hydrogenation of Hybrid CO2 -CO Feeds

The impact of carbon monoxide on CO₂ -to-methanol catalysts has been scarcely investigated, although CO will comprise up to half of the carbon feedstock, depending on the origin of CO₂ and process configuration. In this study, copper-based systems and ZnO-ZrO₂ are assessed in cycling experiments with hybrid CO₂ -CO feeds and their CO sensitivity is compared to In₂ O₃ -based materials. All catalysts are found to be promoted upon CO addition. Copper-based systems are intrinsically more active in CO hydrogenation and profit from exploiting this carbon source for methanol production, whereas CO induces surplus formation of oxygen vacancies (i. e., the catalytic sites) on ZnO-ZrO₂ , as in In₂ O₃ -based systems. Mild-to-moderate deactivation occurs upon re-exposure to CO₂ -rich streams, owing to water-induced sintering for all catalysts except ZnO-ZrO₂ , which responds reversibly to feed variations, likely owing to its more hydrophobic nature and the atomic mixing of its metal components. Catalytic systems are categorized for operation in hybrid CO₂ -CO feeds, emphasizing the significance of catalyst and process design to foster advances in CO₂ utilization technologies.

Generation of Elemental Fluorine through the Electrolysis of Copper Difluoride at Room Temperature

The safe generation of F₂ gas at room temperature by using simple cell configurations has been the "holy grail" of fluorine research for centuries. Thus, to address this issue, we report generation of F₂ gas through the electrolysis of CuF₂ in a CsF-2.45HF molten salt without the evolution of H₂ gas. The CuF₂ is selected through a series of thermodynamic and kinetic assessments of possible metal fluorides. Anode assessments on graphite and glass-like carbon demonstrate the effect of the absence of the anode during generation of F₂ gas owing to stabilized operations at room temperature. Although the Ni anode dissolves during electrolysis in the conventional medium-temperature cell, herein, it facilitates stable electrolysis over 100 h, achieving an F₂ gas purity of over 99 % with the potential to operate using one-compartment electrolysis. This work presents a safe and propitious method for the generation of high-purity F₂ gas for small-scale lab and industrial applications.