| 摘要: | 本研究以自製觸媒包括CeO2、CeO2/HA(氫氧基磷灰石)、CeO2/AC(活性
碳)及CeO2/HA/AC等4種觸媒與H2O2在常壓下共同催化苯胺之濕式過氧化反應(CWPO)，藉由苯胺的轉化率及COD去除率的高低探討不同反應條件之催化苯胺效果。
研究結果顯示，對於四種不同煅燒溫度之CeO2觸媒(250℃、350℃、450℃、550℃)對苯胺水溶液之反應效能，以煅燒溫度450℃之CeO2觸媒之反應效能為最佳，在苯胺100ppm、溫度60℃與0.2M H2O2之條件下，4hr之苯胺轉化率與礦化率分別為80%與60%，故以此觸媒為最適煅燒溫度觸媒再分別與氫氧基磷灰石(HA)及活性碳(AC)分別製得CeO2/HA與CeO2/AC之擔體氧化鈰觸媒，以不同比例之CeO2/HA觸媒(觸媒：擔體 1：1、1：1/2、1：1/4、1：1/8、1：1/16)，對100ppm苯胺溶液進行CWPO反應，結果顯示以CeO2/HA比例為1：1/8之反應效能最佳，在60℃與0.2M H2O2下，4hr之轉化率與礦化率分別為85%及70%。
另藉由不同反應條件之研究顯示，使用1：1/8之CeO2/HA觸媒，其最佳之反應條件：苯胺濃度100ppm、觸媒添加量1g/L、H2O2 0.3M、H2O2 一次添加、起始pH值為6，其反應4hr後之轉化率與礦化率分別為86.6%與80.8%。
經由XRD觸媒鑑定顯示，CeO2觸媒之晶相強度隨煅燒溫度增加而增加；而擔體觸媒CeO2/HA之晶相強度則隨HA之添加比例之減少而增加，另外藉由EDS驗證CeO2/HA及CeO2/AC之添加比例無誤。
在CeO2/AC之擔體氧化鈰觸媒方面，以不同比例之CeO2/AC(觸媒：擔體 1：1、1：1/2、1：1/4、1：1/8、1：1/16)，對100ppm苯胺溶液進行CWPO反應，其反應效能隨擔體比例之減少而有增加之趨勢，其效能最高者為1：1/8之CeO2/AC觸媒，其在溫度60℃與H2O2添加量為0.2M時，4hr之轉化率與礦化率分別為70%及65%。
將CeO2同時與HA、AC依不同比例合成(CeO2：HA：AC 1：1/8：1/8、1：1/16：1/16、1：1/8：1/16、1：1/16：1/8)同樣對100ppm苯胺進行CWPO反應，結果顯示以比例為1：1/8：1/8之CeO2/HA/AC觸媒之反應效能最佳，其4小時轉化率與礦化率分別為57%與48%。
In this study, we prepared four self-made catalysts including CeO2 , CeO2/HA(hydroxyl apatite) , CeO2/AC (activity carbon) and CeO2/HA/AC 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 COD removal.
The result showed that, calcination temperature of 450℃ of CeO2 catalyst was the most active one among the four calcination temperature of 250℃, 350℃,450℃ and 550℃, it performed 80% of conversion and 60% of COD removal at 60℃, 0.2 M H2O2 and 100ppm aniline. Hence we prepared difference ratio of CeO2/HA and CeO2/AC by the most active CeO2 catalyst (calcination temperature at 450℃) for the further study. 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 performced the most active among the five , at the condition of 100ppm of aniline, 60℃ and 0.2M H2O2 , the conversion and COD removal after 4hrs reaction were 85% and 70% , respectively.
Another study by different reaction condition which performed the best was: aniline concentration of 100ppm, catalyst loading 1g/L, H2O2 0.3M by adding once and initial pH at 6, the reaction conversion after 4 hrs and mineralization rates were 86.6% and 80.8%, respectively.
The characterization of catalysts of XRD showed, the CeO2 catalyst crystal phase strength increased when the calcination temperature rose, while the CeO2/HA catalyst phase intensity increased as the ratio of HA reduced, also the proportion of element of CeO2/HA and CeO2/AC were verified by EDS.
For the CeO2/AC catalyst , among the ratio of CeO2/AC (catalyst：support were 1 : 1, 1 : 1/2, 1 : 1/4, 1 : 1/8, 1 : 1/16), the 1 : 1/8 of CeO2/AC catalyst performed the most active among the five, the reaction efficiency increased as the ratio of AC reduced, at the condition of 100ppm of aniline, 60℃ and 0.2M H2O2, the conversion and COD removal after 4 hrs were 70% and 65%, respectively, which was inferior to 1：1/8 of CeO2/HA catalyst.
For the CeO2/HA/AC catalyst of different ratio (1 : 1/8 : 1/8, 1: 1/8 : 1/16, 1 : 1/16 : 1/8, 1 : 1/16 : 1/16), the 1 : 1/8 : 1/8 of CeO2/HA/AC catalyst performanced the most active among the four, at the condition of 100ppm of aniline, 60℃ and 0.2M H2O2 the conversion and COD removal after 4 hrs were 57% and 48%, respectively. |
