## 3 Results  
### Samples Characterization  
The X-ray diffractogram showed broad peaks (Figure 1) typical of a boehmite structure of low crystallinity or highly hydrated boehmite [29] verifying that the material synthesized was as expected. Thus reflections of the prepared sample appeared at 2 theta (\({}^{\circ}\)) = 14, 28, 38, 49, 65, 70 and 85, and they were assigned to an orthorhombic \(\gamma-\)AlOH. Compared with the standard diffraction peaks (JCPDS Card No. 21-1307), no other peaks were observed. The thermogravimetric analysis (TGA) of the synthesized material is represented in Figure 2. The TG curve (blue line) showed a continuous weight loss and according to some research in the literature [30], the TG temperature range has been divided into four regions: Zone I (25-180 \({}^{\circ}\)C) was attributed to the loss of physisorbed water and there may be a loss of physisorbed gases. Zone II was associated with the decomposition of boehmite forming water (180-400 \({}^{\circ}\)C). Some studies have found combustion peaks attributed to surfactants in this temperature range [30]. Zone III (400-730 \({}^{\circ}\)C) was attributed to the elimination of residual carbon compounds and sulfur oxides that remained after the preparation of alumina with Al\({}_{2}\)(SO\({}_{4}\))\({}_{3}\) and the resulting water release of the phase that changes to \(\gamma-\)Al\({}_{2}\)O\({}_{3}\)[31]. Specifically, this change was between 370 and 630 \({}^{\circ}\)C, and is produced by dehydroxylation and transformation of boehmite to \(\gamma-\)Al\({}_{2}\)O\({}_{3}\)[32]. In zone IV (750-1000 \({}^{\circ}\)C) the typical phase changes of \(\gamma\rightarrow\delta\), and \(\theta\rightarrow\alpha\) Al\({}_{2}\)O\({}_{3}\) took place. The DTG curve evidenced several peaks associated to these weight losses. At low temperature, two peaks at 50 and 80 \({}^{\circ}\)C were present and correspond to evaporation of adsorbed water and or physisorbed gases. In the second-third temperature range the two observed peaks were attributed to the dehydroxylation of boehmite to form \(\gamma-\)Al\({}_{2}\)O\({}_{3}\) and finally, the fourth peak was associated to phase changes [33]. These results indicated that the activation of the material synthesized inside the chromatographic column is possible at temperatures below 200 \({}^{\circ}\)C without phase transformation. Considering the Infrared spectrum of boehmite (Figure 3a), in the OH stretching region it is evidenced that, besides the quite sharp bands assigned to surface hydroxyl groups (3800-3500 cm\({}^{-1}\)), a broad absorption was present in the region 3500-2500 cm\({}^{-1}\) and assigned to H-bonded groups [34]. Moreover, the sharp band near 1078-1150 cm\({}^{-1}\) was due to the asymmetric stretching of the internal AlO\({}_{4}\) tetrahedra; and the two contributions at about 900 and 700 cm\({}^{-1}\) were attributed to symmetric bending of O-Al-O groups. The water of hydration produced a band at 1550-1800 cm\({}^{-1}\) region, present in both samples [34]. These vibrations were also present in the sample of \(\gamma-\)Al\({}_{2}\)O  
Figure 1: XRD of pseudoboehmite. (Figure 3b), although slightly more intense. Only the band at 700 cm\({}^{-1}\), belonged to Al = O groups in boehmite [35], was less intense. It was observed a small band in 2400 cm\({}^{-1}\), apparently caused by molecular CO\({}_{2}\). If both spectra are compared, significant differences in the intensity of the bands are found. The intensities of all peaks were strongest for \(\gamma\)-Al\({}_{2}\)O\({}_{3}\). Information about the morphology was obtained from SEM microscopy. Various morphologies of boehmite nanostructures were observed, such as nanosheets (Figure 4a) and nanoparticles (Figure 4b) with flowerlike three-dimensional nano-architectures (Figure 4c). The nanosheet morphologies of boehmite have been seen in other investigations [35]. Nanoparticles were also observed by [PERSON] et al. [36]. Finally, flowerlike three-dimensional nanoarchitectures of boehmite have been observed by [PERSON] et al. [37].