A practical concept for catalytic carbonylations using carbon dioxide

Abstract

The rise of CO₂ in atmosphere is considered as the major reason for global warming. Therefore, CO₂ utilization has attracted more and more attention. Among those, using CO₂ as C1-feedstock for the chemical industry provides a solution. Here we show a two-step cascade process to perform catalytic carbonylations of olefins, alkynes, and aryl halides utilizing CO₂ and H₂. For the first step, a novel heterogeneous copper 10Cu@SiO₂-PHM catalyst exhibits high selectivity (≥98%) and decent conversion (27%) in generating CO from reducing CO₂ with H₂. The generated CO is directly utilized without further purification in industrially important carbonylation reactions: hydroformylation, alkoxycarbonylation, and aminocarbonylation. Notably, various aldehydes, (unsaturated) esters and amides are obtained in high yields and chemo-/regio-selectivities at low temperature under ambient pressure. Our approach is of interest for continuous syntheses in drug discovery and organic synthesis to produce building blocks on reasonable scale utilizing CO₂.

Fig. 1. Catalytic carbonylations using carbon dioxide.

Selective copper-catalyzed CO generation from CO₂ and direct utilization in carbonylation reactions.

Fig. 2. Catalyst characterizations.

a STEM-HAADF images, EDXS and FFT/IFFT of fresh 10Cu/SiO₂-PHM sample. b XPS spectra of 10Cu@SiO₂-PHM, 10Cu@SiO₂-CIM, and 10Cu@SiO₂-PHM-spent samples. c In situ FTIR spectra of 10Cu@SiO₂-PHM and 10Cu@SiO₂-CIM catalysts obtained at 400 °C before and after 60 min exposure to CO₂/H₂ (left) and CO adsorbate spectra measured at room temperature after the in situ experiment (right).

Fig. 3. Catalytic stability test for CO₂ conversion (XCO₂) and CO selectivity (S_CO).

Reaction conditions: 300 mg of 10Cu@SiO₂-PHM, 100 NmL/min of H₂/CO₂ (3:1) gas mixture, gas hourly space velocity (GHSV) = 15,000 h⁻¹, temperature (T) = 400 °C, pressure (P) = 20 bar.

Fig. 4. Cu-catalyzed selective CO₂-to-CO conversion and the follow-up utilization in carbonylation reactions.

a Hydroformylation of alkenes. b Alkoxycarbonylation of alkynes. c Aminocarbonylation of aryl halides.