掺杂修饰TiO_2复合催化剂光催化消除甲醇的研究

Study of Photo-catalytic Elimination of Methanol on TiO_2 Composite Catalysts Modified by Doping

采用酸化-乙醚法合成了H3ASW12O40(AsW),溶胶-凝胶法合成了一系列催化剂(TiO2,TiO2-AsW,TiO2-CeO2,TiO2-ZrO2、TiO2-ZrO2-AsW、TiO2-CeO2-AsW),并用红外光谱,差热-热重分析方法对其进行表征.以甲醇消除反应为模式反应评价催化剂在紫外光照下的光催化性能,考察了制备和反应条件对催化剂性能的影响.在体系流速为2 mL·min-1甲醇的初始浓度为11.7 g·m-3时,ZrO2掺杂量为0.15%时,TiO2-ZrO2(0.15%)复合催化剂光催化消除甲醇达97.6%.CeO2掺杂量为0.2%时,TiO2-CeO(20.2%)复合催化剂的光催化活性最好,甲醇消除率达到99.2%,均优于TiO(296.3%),达到国家大气污染物排放标准.对于三组分TiO2-CeO2(0.2%)-AsW(0.1%)和TiO2-ZrO(20.15%)-AsW(0.1%)复合催化剂在相同条件下催化相同浓度的甲醇时消除率分别为78.8%和86.6%.当初始浓度降为6.8 g.m-3,甲醇在TiO2-CeO(20.2%)复合催化剂上的消除率达到100%.图6,参13.

The H3ASW12O40 （AsW） was prepared by acidification-ether method and a series of photocatalysts TiO2, TiO2-AsW,TiO2-CeO2,TiO2-ZrO2,TiO2-ZrO2-AsW and TiO2-CeO2-AsW were prepaxed by sol-gel method and characterized by IR, TG -DTA analysis. The photocatalytic eliminations of methanol were used as model reactions to evaluate the photocatalytic activity of the composite catalysts under ultraviolet light irradiation. The correlation between the preparation conditions or the reaction conditions and the activity of photocatalytic catalysts were investigated. When the initial concentration of methanol was 11.7 g·m^-3 and the flow rate was 2 mL·min^-1, the eliminate rate of methanol can reach to 99.2% over the TiO2-CeO2 （0.2%） catalyst and to 97.6% over TiO2 - ZrO2 （0.15% ）catalyst, respectively, all are excelled over the TiO2 （ 96.3% ）, meeting the national air pollution emission standard.Under the same conditions, The elimination rate of methanol over the three components TiO2 - CeO2 （0.2%）-AsW （0.1%） and TiO2 -ZrO2 （0.15%）- AsW （0.1%） composite catalysts is 78.8% and 86.6% respectively under the above stone conditions. When the initial concentration of methanol lowers to 6.8 g·m^-3, the eliminate rate of methanol can reach to 100% over the TiO2-CeO2 （0.2%） catalyst.