## 2 Experimental  
Nitrosamine N-nitrosonomic (NNN) with purity higher than 98% was supplied from Alfa Aesar. Then, a solution of NNN 0.5% \(w/w\) in methanol was prepared. A SBA-15 with a fiber-like morphology (SBA-15f) was synthesized according to the procedure described by [PERSON] et al. [36]. BASF P123, Tetraethyl orthosilicate (Wacker, >99% purity) and HCl (Merck 37%) were used as reactants. The SBA-15 with platelet-like morphology (SBA-15p) was synthesized according to the procedure described by [PERSON] et al. [37] using Cetil trimethyl ammonium bromide and sodium dodecyl sulphate (Acros Organics, >99% purity), sulphuric acid (Merck, >99% purity), sodium silicate (Schalau, neutral solution pure) and sodium hydroxide (Sigma Aldrich, >98% purity). MCM-41 was prepared as described [PERSON] et al. [38], employing Cetil trimethyl ammonium bromide (Acros Organics, >99% purity), ammonia (merck, 25% solution) and tetraethyl orthosilicate (Wacker, >99% purity). The catalysts obtained were characterized by N\({}_{2}\) adsorption isotherms (using a Quantachrome AUTOSORB-6), DRX (using a Bruker CCD-Apex, diffractometer) and electron microscopy (using a JEOL JSM-840 apparatus). The temperature-programmed desorption (TPD) of ammonia allows for the acidity of the materials to be obtained. The analysis was developed in a Netzsch TG 209 thermobalance. Maintaining a N\({}_{2}\) flow of 45 mL/min, the samples were heated at 500 \({}^{\circ}\)C with a rate of 10 \({}^{\circ}\)C/min. Then, the materials were cooledto 100 \({}^{\circ}\)C, and a flow of ammonia of 35 mL/min was applied during 30 min. Next, in order to remove the physisorbed ammonia, a flow of 45 mL/min of N\({}_{2}\) was applied for 1 h, maintaining the temperature. Finally, the samples were heated to 900 \({}^{\circ}\)C with a rate of 10 \({}^{\circ}\)C/min. The acidity was quantified according to the weight loss observed in the TPD experiment. The Si/Al ratio was determined by X-ray fluorescence (XRF) in a Philips Magix PRO, model PW2400. The characteristics of the SBA-15f, SBA-15p and MCM-41 materials are shown in Table 1 and Figures 1 and 2. The DRX diffractograms showed the typical behavior of these materials. The two SBA-15s show the diffractogram peaks (100), (110) and (200) characteristic of the Pomm symmetry [36]. The diffraction pattern of the MCM-41 obtained is also characteristic of this aluminosilicate. The morphology of these materials was observed in the SEM micrographs (Figure 2). The SBA-15 presented a fiber-like (SBA-15f) and platelet-like (SBA-15p) morphology, and MCM-41 showed the particulate aspect of this material. TG/FTIR were run in a Mettler Toledo TGA/DSC 1 STARe coupled to a FTIR Bruker Tensor 27. The transfer line was maintained at 200 \({}^{\circ}\)C. The temperature program was 20 min at 40 \({}^{\circ}\)C, heating at 35 \({}^{\circ}\)C/min up to 800 \({}^{\circ}\)C and holding temperature during 5 min. 80 mL/min of N\({}_{2}\) (99.9992%) or air synthetic (21% O\({}_{2}\) and 79% N\({}_{2}\)) were used as the entrained gas in the corresponding experiments. FTIR spectra were obtained at four scans per second between 600 and 4000 cm\({}^{-1}\). The other series of experiments were carried out under flash conditions in a multi-shot pyrolyzer model EGA/PY-3030D, supplied by Frontier Laboratories, and directly coupled on a GC/MS (gas chromatograph Agilent 6890N with electron-impact mass selective detector Agilent 5973). To separate the compounds, an UAS-30M-0.25F column was used with 2 mL/min flow. The experimental conditions used were: an isothermal ramp at 45 \({}^{\circ}\)C during 5 min, a dynamic ramp until 285 \({}^{\circ}\)C at 12 \({}^{\circ}\)C/min and a final isothermal of 5 min, with a 50:1 split ratio. The decomposition of NNN nitrosamine was studied under two atmospheres at different temperatures.