Delaminated hydrotalcite precursors for green methanol synthesis

Abstract

Co-precipitation was used to prepare a copper, zinc, and aluminium hydrotalcite-like precursor to make a methanol synthesis catalyst. Treatment of the wet precursor with an aqueous miscible organic solvent led to the delamination of the sheet-like structure of the precursor phase, dramatically increasing the surface area to 340 m2 g−1 in comparison to 22 m2 g−1 for the untreated material. We show that the copper is initially sequestered within the hydrotalcite phase, and during calcination a CuO phase evolves out from the lamellar structures. Reduction proceeds to Cu0, and neither the calcination nor reduction of the material cause the loss of the lamellar morphology. This leads to high Cu0 surface areas in the final catalyst (66 m2 g−1) and high activity in the methanol synthesis reaction.

Keywords

• Green methanol
• CO2 hydrogenation
• Methanol synthesis
• Hydrotalcite
• Delamination
• Copper catalyst