## 3 Results and Discussion
### Thermal Transformations of Model Lignin Compounds on the Surface of CeO\({}_{2}\)
#### 3.2.4 Ferulic Acid
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline
**Pychysis Product or** **Its Fragment Ion** & **Scheme** & **m/z \({}^{1}\)** & \(I\), a.u.** & \(\begin{array}{c}T_{\text{mapp}}\\ \mathbf{C}\end{array}\) & \(\begin{array}{c}T_{\text{mapp}}\\ \mathbf{T_{\text{mapp}}}\end{array}\) & \(\begin{array}{c}\mathbf{n}\\ \mathbf{C}\end{array}\) & \(\begin{array}{c}\mathbf{E}^{\prime}\mathbf{k}\mathbf{/mol}\end{array}\) & \(\begin{array}{c}\mathbf{v_{0}}\\ \mathbf{s}\end{array}\) & \(\begin{array}{c}\Delta S^{\prime\prime}\\ \mathbf{all}(\mathbf{C}\times\mathbf{mol})\end{array}\) & \(\mathbf{R^{12}}\) \\ \hline \multicolumn{10}{c}{FA} \\ \hline Phenol & 7 & 94 & 0.107 & 250\(-\)570 & 407 & 1 & 118 & \(5.013\times 10^{6}\) & \(-\)29 & 0.949 \\ \hline Guaiocol & 6 & 124 & 0.139 & 150\(-\)375 & 260 & 1 & 78 & \(1.665\times 10^{6}\) & \(-\)36 & 0.957 \\ \hline
4-Vinylguasiocol & 2 & 150 & 3.0 & 70-200 & 120 & - & - & - & - \\ \hline
4-Vinylguasiocol & 3 & 150 & 2.2 & 100-400 & 220 & - & - & - & - \\ \hline
4-Vinylmethylguasiocol & 8 & 164 & 0.209 & 188-427 & 332 & 1 & 109 & \(1.628\times 10^{7}\) & \(-\)27 & 0.984 \\ \hline
4-Vinyldimethylguasiocol & 8 & 178 & 0.047 & 237-432 & 318 & 1 & 114 & \(4.200\times 10^{7}\) & \(-\)25 & 0.951 \\ \hline Naphthalene & - & 128 & 0.04 & 320-520 & 430 & - & - & - & - \\ \hline \multicolumn{10}{c}{VA} \\ \hline Phenol & 2 & 94 & 0.05 & 295-471 & 382 & 1 & 121 & \(1.371\times 10^{7}\) & \(-\)27 & 0.965 \\ \hline Cresol & - & 108 & 0.023 & 238-374 & 322 & 1 & 137 & \(3.383\times 10^{9}\) & \(-\)16 & 0.944 \\ \hline Guaiocol & & 124 & 0.067 & 193-390 & 275 & 1 & 91 & \(1.575\times 10^{6}\) & \(-\)31 & 0.938 \\ Guaiocol & 1 & 109 & 0.097 & 190-411 & 276 & 1 & 90 & \(1.124\times 10^{6}\) & \(-\)32 & 0.905 \\ \hline Vanillin & & 81 & 0.087 & 190-397 & 274 & 1 & 82 & \(1.743\times 10^{6}\) & \(-\)35 & 0.937 \\ \hline \multicolumn{10}{c}{\({}^{1}\) \(m/z\) ratio of ion mass to ion charge \({}^{2}\)\({}^{1}\)\({}^{2}\)\({}^{3}\), coefficient of determination} \\ \hline \end{tabular}
\end{table} 
Table 9: Kinetic parameters (temperature of the maximum desorption rate T\({}_{\text{mapp}}\), reaction order \(n\), activation energy \(E^{\prime}\), pre-exponential factor \(v_{0}\), and change of activation entropy \(\Delta S^{\prime\prime}\)), temperature range (T\({}_{\text{mapp}}\)) of formation and peak intensities (I) of the catalytic reactions of vanillie and freultic acids during pyrolysis over nanocon catalyst. The formation of phenol was characterized by similar kinetic parameters for both vananilic and ferulic acids. The value of the activation energy was \(\sim\)120 kJ mol\({}^{-1}\), and the change in the entropy of activation is \(\sim\)28-29 (cal K\({}^{-1}\) mol\({}^{-1}\)). Close kinetic parameters were observed for the formation of guaiacol for both vananilic and ferulic acids. This indicates that FA and VA have common pyrolysis pathways, probably due to thermal transformations of the same types of surface complexes. The processes of the formation of methylated products such as cresol in the case of VA and methylated 4-vinylguaiacols in the case of FA are also characterized by close temperatures of the maximum desorption rate of \(\sim\)318-332 \({}^{\circ}\)C (Table 8).