Development of Catalytic Decomposition of Chlorofluorocarbon in the Presence of Butane

研究了碳氢化合物存在下氯氟烃(CFCs)的催化氧化分解。前期工作发现，WO_3/Al_2O_3-ZrO_2催化剂对CFC-115具有较高的催化活性。本文考察了催化反应的特殊性，并在不同摩尔比的WO_3/Al_2O_3-ZrO_2催化剂上进行了催化分解反应。在Al_2O_3-ZrO_2摩尔比为0.5-4的范围内，CFC-115的转化率保持不变。在钨糖氧化物含量为2.2-9wt%的范围内，也表现出类似的趋势。掺铂催化剂对CFC-12的催化活性最高。然后，在铂掺杂催化剂上进行了CFC-12的氧化分解。掺铂催化剂比不掺…的催化剂活性高得多更多的掺氮催化剂。因此，可以认为Pt掺杂抑制了WO_3/Al_2O_3-ZrO_2催化剂上活性中心的氟化。在不同C_4H_&lt；10&gt；/CFC-12配比下，对催化剂进行了催化裂解反应。WO_3/Al_2O_3-ZrO_3催化剂在C4H&lt；10&gt；/CFC-12摩尔比为0.5~1的范围内对CFCs表现出较高的催化活性。为探讨Al_2O_3-ZrO_2载体的固体酸度与活性的关系，用NH3-TPD法测定了不同ZrO_2含量的Al_2O_3-ZrO_2载体的固体酸量。Al_2O_3-ZrO_2的固体酸度随ZrO_2含量的增加而降低。然而，在无烃条件下，氧化锆摩尔分数为0.2的Al_2O_3-ZrO_2载体对CFC-12的氧化分解活性最高。这些结果表明，催化剂的活性与酸性强度和活性种类有关。较少

We have investigated the catalytic oxidative decomposition of chlorofluorocarbons (CFCs) in the presence of hydrocarbons. In our previous work, it was found out that WO_3/Al_2O_3-ZrO_2 catalyst exhibited a high activity for CFC-115. In this work, the particicality of the catalitic reaction was investigated.The oxidative decomposition of CFC-115 in the presence of butane was carried out over various molar ratios WO_3/Al_2O_3-ZrO_2 catalysts. The CFC-115 conversion was constant in the range of Al_2O_3-ZrO_2 molar ratios from 0.5 to 4. The similar tendency was shown in the range of tungsuten oxides contents from 2.2 to 9wt%.WO_3/Al_2O_3-ZrO_2 catalysts doped with various metal oxides were investigated for the oxidative decomposition of CFC-12 in the presence of butane at low temperatures. The Pt doped catalyst exhibitedmthe highest activity for CFC-12. Then, the oxidetive decomposition of CFC-12 was carried out over the Pt-doped catalyst. The Pt-doped catalyst was much more active than no … More n-doped catalyst. Thus, it is considered that the WO_3/Al_2O_3-ZrO_2 catalyst was depressed the fluorination of active sites by doping with Pt.The decomposition of CFC-12 in the presence of butane were carried out under various C_4H_<10>/CFC-12 ratios over WO_3/Al_3O_3-ZrO_2 catalyst. The WO_3/Al_2O_3-ZrO_3 catalyst exhibited a high activity for CFC-12 in the range of C_4H_<10>/CFC-12 molar ratios from 0.5 to 1.It was found that the high activity of WO_3/Al_2O_3-ZrO_2 catalyst for CFCs is caused by the solid acidity of the catalyst. In order to investigate the relationship betwteen solid acidity and activity of Al_2O_3-ZrO_2 carrier, the amount of solid aciditiy of Al_2O_3-ZrO_2 carrier various ZrO_2 content was measured by NH3-TPD method. The amount of solid acidity of Al_2O_3-ZrO_2 decreaced with an increace in ZrO_2 content. However, Al_2O_3-ZrO_2 carrier with a ZrO_2 molar fraction of 0.2 was the most active for the oxidative decomposition of CFC-12 in the absence of hydrocarbons over the carrier used as a catalyst. These results suggests that the catalytic activity participates in the acidic strength and kind of activity. Less