# Tunable Effect of the Calcination of the Silanol Groups of KIT-6 and SBA-15 Mesoporous Materials
## 3 Results and Discussion
### Effect of the Calcination Temperature on the Silanol Groups  
The results of \({}^{29}\)Si solid-state CP-MAS NMR experiments are shown in Figure 6. The literature [69] reports three characteristic resonance peaks for these types of materials at \(-110\) ppm, \(-101\) ppm, and \(-92\) ppm, corresponding to species Q\({}^{4}\) (siloxane, Si(OSi)\({}_{4}\)), Q\({}^{3}\) (vicinal silanol, Si(OSi)\({}_{3}\)(OH)) and Q\({}^{2}\) (geminal silanol, Si(OSi)\({}_{2}\)(OH)\({}_{2}\)). Table 5 gives an overview of the meaning peaks characteristics, showing the position of the peaks, these intensities and the corresponding integration peaks of each specie, calculated in terms of percentage [78]. Figure 6 is a qualitative analysis and its results must be compared with some quantitative dates. In this manner, the Table 5 gives additional information showing that the integrations percentages areas oscillate between 13.8-16.1%, 69.3-73.4%, and 11.6-15.1% for SBA-15 samples, respectively, in the peaks Q\({}^{2}\), Q\({}^{3}\), and Q\({}^{4}\), considering only the calculated samples. In the same way, for the KIT-6 samples, the integration percentage areas oscillate between 11.8-16.9%, 67.8-77.3%, and 10.4-16.0%, respectively, in the peaks Q\({}^{2}\), Q\({}^{3}\), and Q\({}^{4}\), considering only the calculated samples. The position of the peaks is in accordance with literature [69]. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Samples** & **Signal** & **\(\boldsymbol{\xi}\) (ppm)** & **Intensity** & **Area (\%)** \\ \hline \multirow{3}{*}{SM0} & Q\({}^{2}\) & \(-91.3\) & \(127\) & \(8.0\) \\  & Q\({}^{3}\) & \(-101.3\) & \(549\) & \(65.8\) \\  & Q\({}^{4}\) & \(-110.3\) & \(228\) & \(26.2\) \\ \hline \multirow{3}{*}{SM1} & Q\({}^{2}\) & \(-91.2\) & \(145\) & \(15.9\) \\  & Q\({}^{3}\) & \(-100.5\) & \(455\) & \(72.5\) \\  & Q\({}^{4}\) & \(-109.7\) & \(76\) & \(11.6\) \\ \hline \multirow{3}{*}{SM2} & Q\({}^{2}\) & \(-91.4\) & \(39\) & \(16.1\) \\  & Q\({}^{3}\) & \(-100.5\) & \(123\) & \(72.3\) \\  & Q\({}^{4}\) & \(-109.0\) & \(25\) & \(11.6\) \\ \hline \multirow{3}{*}{SM3} & Q\({}^{2}\) & \(-91.6\) & \(662\) & \(13.8\) \\  & Q\({}^{3}\) & \(-100.3\) & \(2227\) & \(73.4\) \\  & Q\({}^{4}\) & \(-109.0\) & \(516\) & \(12.8\) \\ \hline \multirow{3}{*}{SM4} & Q\({}^{2}\) & \(-91.1\) & \(740\) & \(14.8\) \\  & Q\({}^{3}\) & \(-100.2\) & \(2308\) & \(72.0\) \\  & Q\({}^{4}\) & \(-108.1\) & \(548\) & \(13.2\) \\ \hline \multirow{3}{*}{SM5} & Q\({}^{2}\) & \(-91.3\) & \(160\) & \(16.0\) \\  & Q\({}^{3}\) & \(-100.4\) & \(449\) & \(70.5\) \\  & Q\({}^{4}\) & \(-108.1\) & \(126\) & \(13.5\) \\ \hline \multirow{3}{*}{SM6} & Q\({}^{2}\) & \(-91.2\) & \(746\) & \(15.6\) \\  & Q\({}^{3}\) & \(-100.1\) & \(1931\) & \(69.3\) \\  & Q\({}^{4}\) & \(-109.7\) & \(439\) & \(15.1\) \\ \hline \multirow{3}{*}{KM0} & Q\({}^{2}\) & \(-91.2\) & \(196\) & \(16.9\) \\  & Q\({}^{3}\) & \(-100.8\) & \(605\) & \(67.8\) \\  & Q\({}^{4}\) & \(-109.8\) & \(142\) & \(15.3\) \\ \hline \multirow{3}{*}{KM1} & Q\({}^{2}\) & \(-91.4\) & \(315\) & \(16.1\) \\  & Q\({}^{3}\) & \(-100.5\) & \(961\) & \(72.2\) \\  & Q\({}^{4}\) & \(-108.9\) & \(188\) & \(11.7\) \\ \hline \multirow{3}{*}{KM2} & Q\({}^{2}\) & \(-91.2\) & \(105\) & \(14.6\) \\  & Q\({}^{3}\) & \(-100.1\) & \(362\) & \(75.0\) \\  & Q\({}^{4}\) & \(-109.0\) & \(64\) & \(10.4\) \\ \hline \multirow{3}{*}{KM3} & Q\({}^{2}\) & \(-91.5\) & \(73\) & \(15.0\) \\  & Q\({}^{3}\) & \(-100.3\) & \(204\) & \(73.8\) \\ \cline{1-1}  & Q\({}^{4}\) & \(-109.0\) & \(39\) & \(11.2\) \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Parameters of \({}^{1}\)H decoupled \({}^{29}\)Si solid-state MAS NMR spectra of SBA-15 and KIT-6 samples. Figure 6: \({}^{1}\)H decoupled \({}^{29}\)Si solid-state magic-angle spinning (MAS) nuclear magnetic resonance (NMR) spectra of the SBA-15 and KIT-6 samples calcined under different conditions.