脱硝催化剂用堇青石多孔陶瓷的制备与性能研究

以偏高岭土、氧化铝和滑石为原料,利用压制成型制备出堇青石多孔陶瓷并采用浸渍涂覆法制备锰基低温脱硝催化剂.通过气孔率、抗折强度、热膨胀系数、SEM、BET等测试探究了碳粉和淀粉两种造孔剂及添加量、不同酸处理时间等因素对堇青石性能的影响并考察了不同浸渍次数的催化剂在80~200 ℃间的脱硝性能.结果表明:造孔剂为碳粉且添加量为4%时,得到的堇青石具有良好的性能,此时气孔率达31.12%,热膨胀系数为3.10×10-6/K,抗折强度为21.41 MPa;适当的酸处理有助于堇青石表面孔结构的丰富且能大幅提升其比表面积,最佳处理时间为2 h;当浸渍次数为4次时,整体式催化剂的性能最佳,牢固度可达90.18%,140 ℃时的脱硝率可达74.5%以上.

Preparation and Properties of the Porous Cordierite Ceramic for Catalystic Denitration

Porous cordierite ceramic was prepared by compression molding method with raw materials meta-kaolin, Al2O3 and talc and the denitration catalyst was obtained with impregnation coating method.The porosity, bending strength, thermal expansion coefficients, SEM, BET and other testing methods were used to investigate the effect of porous cordierite ceramics including type and content of the pore-forming agent and acid treatment.The catalytic performance was investigated with different loading rates between 80 ℃ and 200 ℃.The results show the cordierite owned excellent performance with the addition of carbon at 4%.In this condition, the porosity, bending strength and thermal expansion coefficients can reach 31.12%, 21.41 MPa, 3.10×10-6/K respectively.2 h is a perfect acid treatment time that can rich surface pore structure and enlarge surface area significantly.The integral denitration catalyst is obtained with excellent performance at low temperature when the impregnation time is 4.The firmness can be 90.18% and its efficiency of denitration will be 74.5% at 140 ℃.