MFI/BEA双沸石复合物的合成及其在甲烷选择性还原NO_x中的应用  

Bi-phase Zeolites Composite MFI/BEA: Synthesis and Application in Selective Catalytic Reduction of NO_x by Methane

作　　者：李彪[1] 张鸿雁[1] 郑家军[1] 秦波[2] 潘梦[1] 陈佳琪[1] 于峰[1] 王广帅[1] 李瑞丰[1] 

机构地区：[1]太原理工大学能源化工与催化研究中心,太原030024 [2]中石化抚顺石油化工研究院,抚顺113001

出　　处：《无机化学学报》2015年第8期1563-1570,共8页Chinese Journal of Inorganic Chemistry

基　　金：国家自然科学基金委-中石化联合基金(No.U1463209);国家自然科学基金(No.21371129;21376157;51272169)资助项目

摘　　要：以合成的β沸石固液混合物作为ZSM-5沸石的部分原料制备了含有ZSM-5和β沸石的双相沸石复合物MFI/BEA。采用XRD,FTIR,吡啶红外,NH3-TPD,TEM,SEM和氮吸附-脱附等对合成的材料进行了表征。结果表明后合成的ZSM-5沸石在β沸石内部孕育生长,MFI/BEA双沸石复合物中两相沸石的组成比例可以通过控制第二步晶化时间来进行有效调控;与单一的CoZSM-5或Co-β相比,通过离子交换法制备的Co-基复合催化剂Co-MFI/BEA在富氧条件下甲烷选择催化还原NO反应中具有高活性和高的稳定性,并且表现出较好的抗SO2毒化性能和良好的可逆性。Zeolite-zeolite composites composed of ZSM-5 and β zeolite crystals were synthesized by a two-step hydrothermal crystallization procedure （denoted as MFI/BEA）, in which the mixture of pre-synthesized β zeolite was used as the nutrients for the growth of the post-synthesized ZSM-5 zeolite. The structural, crystalline, and textural properties of the as-synthesized materials, as well as the references ZSM-5 and β zeolite samples, were characterized by XRD, FTIR, in situ pyridine IR spectroscopy, NHa-TPD, nitrogen adsorption/desorption, TEM and SEM. The results displayed that the post-synthesized ZSM-5 zeolite unexpectedly grew within the β zeolite crystals, and the ratios of MFI/BEA in the as-synthesized zeolite-zeolite composites could be adjusted by controlling the second-step crystalline time. Catalytic performances of Co-β, Co-ZSM-5 and Co-MFI/BEA were investigated during the catalytic reduction of NO by methane in the presence of O2. As compared with the references Co-β and Co-ZSM-5, the zeolite-zeolite composites Co-MFI/BEA exhibited an excellent catalytic performance with a higher activity as well as a higher stability and an excellent sulfur-resistance.

关 键 词：ZSM-5 沸石复合物 逆向生长 脱硝 

分 类 号：O643[理学—物理化学]