Catalytic Decomposition of CFC-12 over Solid Superacid ${\mathrm{Mo}}_{\mathbf{2}}{\mathrm{O}}_{\mathbf{3}}\mathrm{/}{\mathrm{ZrO}}_{\mathbf{2}}$

Catalytic decomposition of dichlorodifluoromethane (CFC-12) in the presence of water vapor and oxygen was studied over a series of solid superacids, ${\mathrm{Mo}}_2{\mathrm{O}}_3/{\mathrm{ZrO}}_2$, that had different ${\mathrm{ZrO}}_2$ content by using a fixed-bed reactor. ${\mathrm{CO}}_2$ and ${\mathrm{CClF}}_3$ were the main products and no CO was detected as by-product. The decomposition activity of solid superacid largely depended on the content of ${\mathrm{ZrO}}_2$ and the calcination temperatures of ${\mathrm{Mo}}_2{\mathrm{O}}_3/{\mathrm{ZrO}}_2$. The optimal calcination temperature and content of ${\mathrm{ZrO}}_2$ for preparing ${\mathrm{Mo}}_2{\mathrm{O}}_3/{\mathrm{ZrO}}_2$ with the highest activity for catalytic decomposition of CFC-12 were 450°C and 20–40% by weight, respectively. Adopting a low concentration of oxygen and CFC-12 together with a high concentration of water vapor was preferable for having the high conversion efficiency of CFC-12 and the selectivity for ${\mathrm{CO}}_2$. The catalytic activity of ${\mathrm{Mo}}_2{\mathrm{O}}_3/{\mathrm{ZrO}}_2$ remained steady for 100 h in continuous operation.