*3.2. Physico-Chemical Characterizations*

The physicochemical properties of the materials were evaluated after each steps of the synthesis. Diffractograms are recorded on a Bruker D8 apparatus, using the CuKα radiation (λ = 1.54059 Å). Data were collected for 2θ between 10◦ and 80◦, with an increment of 0.05◦ and an integration time of 1.0 s at each step. Diffractograms were indexed using references PDF database. Crystallite mean sizes are calculated using the Scherrer equation: *Dcryst* = *(k*·λ*)*/*(*β·*cos*θ*)*, where *k* and β are respectively the shape factor (~0.9) and the corrected full width at half maximum. N2-physisorption experiments were collected on a Micromeritics Tristar II porosity instrument. A known mass of catalyst was degassed at 150 ◦C under vacuum for 6 h. Isotherms were registered at a temperature of −196 ◦C and SSA were determined from the adsorption branch in the 0.05–0.30 P/P0 range with the Brunauer–Emmett–Teller (BET) equation. SEM images were acquired on a JOEL JSM 5300 microscope equipped with EDXS module, allowing elemental quantification. Samples were previously put on a carbon tape and coated with graphitic carbon to reduce charging effect. TEM images were registered on a MET FEI Tecnai G2-20 twin microscope equipped with LaB6 source and providing an electron beam with an acceleration voltage of 200 kV. Samples were dry-deposed on a copper grid without any other treatment. Temperature-programmed reductions were operated on a Micromeritics AutoChem II 2920 chemisorption analyzer. A catalyst mass, fixed to ~40 mg, was inserted in a quartz reactor and degassed under inert gas. A flow of 5 vol.% H2/N2 was stabilized at a total flow rate of 50 mL·min<sup>−</sup>1, and the catalyst was heated from 40 ◦C to 900 ◦C at a temperature increase rate of 10 ◦C·min−<sup>1</sup> (K and P parameters respectively of 88 s and 15 ◦C). X-ray photoelectron spectroscopy analysis was carried out using a Kratos AXIS Ultra DLD apparatus with a monochromated Al Kα (1487 eV) source. Processing was performed using CasaXPS software, spectra being energy-corrected according to the main C 1s peak positioned at 284.8 eV.
