1. FTIR spectra of the original samples
FTIR spectra of the original samples. Vertical lines highlight the shift in the positons of some bands

2. DTA curves for the samples studied, recorded in N2 and in O2

3. Electronic spectra (diffuse reflectance) of the samples studied

4. Nitrogen adsorption isotherms for the samples studied
Nitrogen adsorption isotherms for the samples studied. Solid symbols: adsorption, empty symbols: desorption

5. FTIR spectra of the samples calcined for 3 h at 500 °C in air

6. Percentage changein specific surface area and pore volume upon calcination of CuCo samples at 300 °C for 2 h in air.