Continuous-Flow Hydrogenation of Carbon Dioxide to Pure Formic Acid using an Integrated scCO(2) Process with Immobilized Catalyst and Base

Dual role for CO(2) : Pure formic acid can be obtained continuously by hydrogenation of CO(2) in a single processing unit. An immobilized ruthenium organometallic catalyst and a nonvolatile base in an ionic liquid (IL) are combined with supercritical CO(2) as both reactant and extractive phase.     

Low‐Temperature Hydrogenation of Carbon Dioxide to Methanol with a Homogeneous Cobalt Catalyst

Herein we describe the first homogeneous non‐noble metal catalyst for the hydrogenation of CO₂ to methanol. The catalyst is formed in situ from [Co(acac)₃], Triphos, and HNTf₂ and enables the reaction to be performed at 100 °C without a decrease in activity. Kinetic studies suggest an inner‐sphere mechanism, and in situ NMR and MS experiments reveal the formation of the active catalyst through slow removal of the acetylacetonate ligands.     

Tailor‐made Molecular Cobalt Catalyst System for the Selective Transformation of Carbon Dioxide to Dialkoxymethane Ethers

Herein a non‐precious transition‐metal catalyst system for the selective synthesis of dialkoxymethane ethers from carbon dioxide and molecular hydrogen is presented. The development of a tailored catalyst system based on cobalt salts in combination with selected Triphos ligands and acidic co‐catalysts enabled a synthetic pathway, avoiding the oxidation of methanol to attain the formaldehyde level of the central CH₂ unit. This unprecedented productivity based on the molecular cobalt catalyst is the first example of a non‐precious transition‐metal system for this transformation utilizing renewable carbon dioxide sources.