Creation of Highly Reducible CuO Species by High-Temperature Calcination of a Cu-Al Layered Double Hydroxide: Selective Hydrogenation of Furfural into Furfuryl Alcohol with Formic Acid

Abstract Highly reducible CuO species were created by the calcination of a Cu-Al layered double hydroxide (CuAl LDH) at 1073 K under air. After this heat treatment, the original layered double hydroxide structure was completely transformed into CuO and CuAl2O4 phases. The synthesized calcined CuAl LDH (calc-CuAl LDH) promoted the catalytic hydrogenation of furfural (FALD) into furfuryl alcohol (FOL) with formic acid (FA) as a hydrogen donor. In the initial stage of the above catalytic reaction, the CuO species in the calc-CuAl LDH matrix transformed into active Cu0 species via the formation of a Cu(HCOO)2-1,4-dioxane complex in the liquid phase. The spent catalyst was also reusable without loss of its high catalytic performance.