**3. Results and discussion**

*Microemulsion - A Chemical Nanoreactor*

Subsequent to the formation of the microemulsions, the wet solids were maintained at room temperature for 48 h to evaporate the solvents. The obtained solids

The concentrations of the metallic elements in calcined samples were determined in a Varian SpectrAA 220 FS Atomic Absorption Spectrometer equipment.

The nitrogen physisorption analysis for calcined catalysts was developed in an Autosorb 1 gas sorption system (Quantachrome). Samples were outgassed at 477 K under vacuum for 6 h. Then, nitrogen physisorption experiments were carried out at 77 K. The determination of surface area and volume and pore diameter were

To determine the coordination number and crystallographic arrangements of the synthesized support (alumina), a magic angle spinning-nuclear magnetic resonance equipment (MAS-NMR) Bruker Avance II 300, equipped with a multinuclear detector of 4-mm CPMAS with a frequency range 31P to 15N was utilized. Analyses

The crystalline phases of the calcined samples were identified using a Siemens D-500 Kristalloflex diffractometer, with a CuKα radiation, λ = 0.15406 nm, and with primary and secondary monochromators. The equipment was operated at

Raman spectra for the calcined samples were recorded using Raman HORIBA

Jobin Yvon T64000 equipment. The excitation laser source wavelength was 532.1 nm, with a power of 20 mW at the laser head; 100 scans of each sample were performed and accumulated at room temperature, and the spectra were recorded in

were calcined at 500°C for 6 h, with an air flow of 20 ml/min.

*Diagram for the synthesis method used for preparing the reverse microemulsion.*

The spectrophotometer was calibrated with certified standards.

were carried out with a rotational speed of 10 kHz.

.

carried out using the BET equation and the BJH method, respectively.

35 kV, 20 mA, with a time interval of 1 s and scan rate of 0.03°/s.

**2.2 Characterization**

**Figure 1.**

**96**

the range 100–1300 cm<sup>−</sup><sup>1</sup>
