表面活性剂辅助水热热分解法制备介孔氧化铝纤维

以PEG(Mn=20000)为模板导向剂, 尿素为沉淀剂, 采用水热热分解法制备了纳米介孔结构的氧化铝纤维, 并对其吸附性能进行了研究. 通过X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、热释重仪(TGA)和N2等温脱附-吸附分析, 考察了介孔氧化铝纤维的相态、结构、形貌、比表面积和介孔特征. 采用选择性催化还原(SCR)烟气脱硝装置对其吸附性能进行了研究. 结果表明：以PEG为模板, 采用简单的水热法就可得到直径(200～300)nm×(8～10)μm的碳酸铝铵纤维; 经900℃煅烧2h得到比表面积为316m²/g、平均孔径为2.5nm的η-Al₂O₃介孔纤维, 形貌基本不发生变化; SCR烟气脱硝测试显示, 相比商品氧化铝粉末, 合成的氧化铝介孔纤维有着更强的吸附性能, 它的脱硝效率较之商品氧化铝粉末约提高了15%.

Surfactant Assisted Hydrothermal and Thermal-decomposition Synthesis of Alumina Microfibers with Mesoporous Structures

Using template PEG as structure directing agent and urea as the precipitant, alumina microfibers with mesoporous structures were successfully synthesized from a hydrothermal preparation and thermal-decomposition of precursor of ammonium aluminum carbonate hydroxide (denoted as AACH), and its adsorbability was also investigated. The phase state, chemical structure, surface morphology, special surface areas and mesoporous structure of the synthesized alumina microfibers were characterized systemically by means of XRD, SEM, TEM, TG/DTA, and N₂ adsoption-desoption techniques, respectively. The adsorptive property of the obtained mesoporous alumina fibers was examined by using a typical SCR(Selective Catalytic Reduction) denitrification facility. The results show that the AACH microfibers with diameter of about 200-300nm and length up to 8μm or 10μm are prepared by using PEG as template. The mesoporous η-Alumina microfibers with specific surface area 316m²/g and average pore diameter 2.5nm are obtained after calcined at 900℃ for 2h, and the morphology is retained in the calcination process. SCR denitrification tests show that the as-prepared mesoporous alumina microfibers exhibit more favorable adsorptive property and its efficiency of denitrification increases approximately 15% compared with commercial γ-Al2O3 powder.