鈰含量與過氧化氫濃度對CeO2/HA觸媒催化苯胺之濕式過氧化反應之影響

The Effect of Cerium Content and Concentration of Hydrogen Peroxide for the Ceo2/HA Catalyzed Wet Peroxidation of Aniline

本實驗利用自製之二種觸媒，第一種為不同煅燒溫度之CeO2 觸媒，第二種為不同合成比例之CeO2/HA（氫氧基磷灰石），在常壓下對苯胺進行觸媒濕式過氧化反應（Catalytic Wet Peroxide Oxidation，CWPO），藉由苯胺的轉化率與COD 去除率，探討不同反應條件之催化效果。研究結果顯示在未添加觸媒及H2O2 情況下，100ppm苯胺在溫度60℃反應下其4 小時之濃度與COD 值並無明顯之變化，而在添加CeO2 觸媒與H2O2 之後其轉化率及礦化率有明顯上升，顯示CeO2 觸媒與H2O2 之添加對於苯胺具有良好的催化效果。
本研究第一種不同煅燒溫度（250℃、350℃、450℃、550℃） 之觸媒對100ppm 苯胺之反應效能，以煅燒溫度450℃之效能最佳，其在苯胺濃度100ppm、溫度60℃、H2O2 0.2M、觸媒添加量1g/L 之反應條件下，轉化率及礦化率分別達到76%及60%；本研究後續將此觸媒與HA（氫氧基磷灰石）依不同比例（CeO2：HA 之重量比例 1：1、1：1/2、1：1/4、1：1/8、1：1/16）合成擔體氧化鈰觸媒（第二種觸媒），對100ppm 苯胺進行CWPO 反應（溫度60℃、H2O2 0.2M），結果顯示效能最佳擔體氧化鈰觸媒為1：1/8（CeO2：HA），其催化效能優於純氧化鈰觸媒（第一種觸媒）。利用不同濃度之過氧化氫及過氧化氫添加次數對100ppm 苯胺之反應效能，結果顯示以過氧化氫濃度為0.2M、添加次數為一次之反應效能最佳。

In this study, we prepared two self-made catalysts including the first one: CeO2 and the second: CeO2/HA（hydroxyl apatite） for the catalytic wet peroxide oxidation （CWPO） at atmospheric pressure with adding H2O2 of aniline solution. Performance of the catalysts was evaluated via rate of aniline conversion and mineralization （COD removal）.The result showed that, no noticeable aniline conversion was observed after 4hrs reaction of 100ppm aniline at 60℃ without adding CeO2 catalyst and H2O2. However, the efficacy of aniline has much higher performance when CeO2 catalyst and H2O2 were added, which indicated that a better effect on CWPO.The first catalyst we prepared were CeO2, our results indicated that, CeO2 catalyst at calcination temperature of 450℃ was the most active one among the four calcination temperature of 250℃, 350℃,450℃ and 550℃, it performed 76% of aniline conversion and 60% of COD removal at 60℃, 0.2 M H2O2 of 100ppm aniline. Hence we prepared difference ratio of CeO2/HA as the second catalyst by the most active CeO2 catalyst （calcinations temperature at 450℃） for the aniline catalyzing. Among the ratio of CeO2/HA （catalyst：support were 1 : 1 , 1 : 1/2 , 1 : 1/4 , 1 : 1/8 , 1 : 1/16） , the 1：1/8 of CeO2/HA catalyst performed the most active among the five, which was superior to CeO2 catalyst （the first one）. As for the study about reaction condition of H2O2 concentration and H2O2-adding, our data provided the best efficacy was: H2O2 0.2M by adding once at the 1：1/8 of CeO2/HA catalyst loading 1g/L and aniline concentration of 100ppm.