摘要使用浸渍法、沉淀法和溶胶凝胶法制备了TiO2-γ-Al2O3复合载体,并对复合载体以及锐钛矿型TiO2和γ-Al2O3使用分步浸渍法先后负载6wt%WO3和1wt%V2O5制得相应催化剂。模拟NH3-SCR脱硝实际反应条件对不同催化剂脱硝活性进行测试和比较,使用XRD、BET、NH3-TPD等技术对载体和催化剂进行表征。结果表明,在载体和催化剂中TiO2均为锐钛矿型而Al2O3均为γ型,并无明显WO3和V2O5晶型出现。使用沉淀法制备的V-W/Ti-Al复合载体催化剂优于单一组分载体的催化剂,其在较宽活性窗口下有着较高的脱硝效率,并具有较大比表面积,且表面酸性位点较多,有利于氨气在其表面的吸附。最后基于复合载体催化剂的应用前景,对其进行高温热处理实验后检测催化剂的失活及晶型的变化。结果表明使用沉淀法制备的复合载体催化剂经过750℃高温处理后仍能保持很高的活性,且其晶型基本保持稳定。62991
毕业论文关键词 NH3-SCR; 脱硝; Ti-Al复合载体; V2O5; WO3。
毕业设计说明书(论文)外文摘要
Title The Impact of Composite Support for Selective Catalytic Reduction of NO on Vanadium-Based Catalysts .
Abstract A series of titania-alumina composite support were prepared by wet impregnation, precipitation or sol-gel methods. 6wt%WO3 and 1wt%V2O5 were loaded on these composite supports, anatase TiO2 or γ-Al2O3 by step-by-step wet impregnation to prepare catalysts. The DeNOX performance of different catalysts were studied in a simulation of the real reaction conditions, XRD, BET, NH3-TPD were used to investigating the physical and chemical properties of supports and catalysts. The results showed that there were only typical diffraction peaks of anatase phase TiO2 and γ type Al2O3, No significant crystalline V2O5 or WO3 diffraction peak was detected.DeNOX performance of V-W/Ti-Al composite support catalyst prepared by precipitation methods was better than others with a superior NOX conversion in a wider temperature range, larger BET surface area, and more acidic sites which may be benefical to the ammonia adsorption.Based on the practical application considerations, a high temperature treatment was carried out on composite support catalyst in order to investigate its thermal stability and phase transition. The composite support catalyst prepared by precipitation methods maintained a high catalytic activities after a 750℃ heat treatment, and its crystal structure remained stable.
Keywords NH3-SCR; DeNOX; Ti-Al composite support; V2O5; WO3。
1 引言 1
1.1 NOx的危害 1
1.2目前对NOx的生成与控制方法 1
1.2.1 NOx的生成 1
1.2.2 燃烧后NOX控制技术 2
1.2.3 NH3-SCR反应机理研究 2
1.3商用SCR催化剂V-W/Ti 3
1.4 Ti-Al复合载体及其催化剂V-W/Ti-Al 4
1.4.1 Ti/Al复合载体 4
1.4.2 V-W/Ti-Al催化剂 5
1.5研究的内容 5
2 实验 6
2.1主要仪器与试剂 6
2.2催化剂的制备 8
2.2.1 V-W/Ti与V-W/Al催化剂的制备 8
2.2.2复合载体以及催化剂的制备 9
2.3 NH3-SCR固定床反应活性测试 11
2.4 XRD测试