Catalytic Pyrolysis of 2-Chloro-1,1-difluoroethane to Synthesize Vinylidene Fluoride over the Potassium-Promoted Carbon Catalysts

Vinylidene fluoride (VDF) is a crucial monomer for manufacturing polyvinyl fluoride. Catalytic pyrolysis is an ideal route to dispose of 2-chloro-1,1-difluoroethane (HCFC-142) byproduct derived from the industrial manufacture of 1-chloro-1,1-difluoroethane (HCFC-142b). The activated carbon catalysts treated by nitric acid and further supported by potassium, were employed to catalytic pyrolysis of HCFC-142 to synthesize VDF. The prepared K/C catalysts were characterized by BET, X-ray diffraction (XRD), SEM-EDX, Raman, NH3- and CO2- Temperature Programmed Desorption (TPD). With the increase of potassium loading, the surface areas of K/C catalysts reduce gradually, whereas their amounts of surface base sites increase. When the potassium loading reaches up to 1.0%, the 1 K/C catalyst possesses the superior catalytic performance, with the highest conversion of 47.7% and selectivity to VDF of 48.4% at 600 degrees C. The potassium species improved the catalytic performance of activated carbon is associated with the suitable amounts of surface base sites.