Catalytic conversion of 1,1,1,2-tetrafluoroethane (HFC-134a)

摘要

We examined the conversion of HFC-134a over five catalysts, Na~(2)CO~(3), CaO, CaCO~(3), and two types of γ -Al~(2)O~(3)with different surface areas, between 300 and 600 °C. HFC-134a was barely converted via the non-catalytic reaction, even at the highest temperature (600 °C). The operating temperatures for the catalytic conversion of HFC-134a were reduced dramatically and its efficiency increased with increasing temperature. Among the catalysts used, γ -Al~(2)O~(3)with the larger surface area showed the highest conversion rate of HFC-134a, which was followed, in order, by γ -Al~(2)O~(3)with the smaller surface area, CaCO~(3), CaO, and Na~(2)CO~(3). The conversion rate of γ -Al~(2)O~(3)decreased rapidly due to catalyst deactivation. The catalytic efficiency of γ -Al~(2)O~(3)was maintained for a longer period by water addition. Water acted as a hydrogen donor for the dehydrofluorination reaction.