Kinetics of the Thermal Decomposition of CF₄ in the Presence of H₂ at High Temperature

This paper is concerned with the kinetics of the thermal decomposition of tetrafluoromethane in the presence of \mathrmH_2 and a impurity \mathrmCF_3 \mathrmCl in a single-pulse shock tube in the temperature range 1000 to 1080 K . The reactants were highly diluted with argon. The principal reaction products containing tertrafluoromethylene and \mathrmCF_3 \mathrmH. A reaction mechanism involving two-center chains which in compatible with observed products is proposed and the initiation reaction is the broken of \mathrmC-\mathrmCl bond in \mathrmCF_3 \mathrmCl. At pressure P_1=0.1 \mathrmM pa we find the apparant rate constant k_e f f=10^13.7 \exp \left(-\frac55000R T\right) 1^1 / 2 \cdot \mathrm~mol^-1 / 2 \cdot \mathrm~s^-1 and the relational rate constants \beginaligned & k\left(\mathrmCF_3 \mathrmCl \rightarrow \mathrmCF_3 \cdot+\mathrmCl \cdot\right)=10^15 \exp \left(-\frac81000R T\right) \mathrms^-1 \\ & \left.\quad \mathrm~F_3 \cdot+\mathrmH_2 \rightarrow \mathrmCF_3 \mathrmH+\mathrmH \cdot\right)=10^8.6 \exp \left(-\frac8800R T\right) 1 \cdot \mathrm~mol^-1 \cdot \mathrm~s^-1 \\ & k\left(\mathrmCF_4+\mathrmH \cdot \rightarrow \mathrmCF_3 \cdot+\mathrmHF\right)=10^11.4 \exp \left(-\frac20000R T\right) 1 \cdot \mathrm~mol^-1 \cdot \mathrm~s^-1 \\ & k\left(\mathrmCF_3 \cdot+\mathrmH \cdot \rightarrow \mathrmCF_3 \mathrmH\right)=10^8.0 1 \cdot \mathrm~mol^-1 \cdot \mathrm~s^-1 \endaligned