Data underlying the research on: An integrated approach to the key parameters in methanol-to-olefins reaction catalyzed by MFI/MEL zeolite materials

Identification of the catalyst characteristics correlating with the key performance parameters including selectivity and stability is key to the rational catalyst design. Herein we focused on the identification of property-performance relationships in the methanol-to-olefin (MTO) process by studying in detail the catalytic behaviour of MFI, MEL and their respective intergrowth zeolites. The detailed material characterization reveals that both the high production of propylene and butylenes and the large MeOH conversion capacity correlate with the enrichment of lattice Al sites in the channels of the pentasil structure as identified by 27Al MAS NMR and 3-methylpentane cracking results. The lack of correlation between MTO performance and other catalyst characteristics, such as crystal size, presence of external Brønsted acid sites (BAS) and Al pairing suggests their less pronounced role in defining the propylene selectivity. Our analysis reveals that catalyst deactivation is rather complex and is strongly affected by the enrichment of lattice Al in the intersections, the overall Al-content, and crystal size. The intergrowth of MFI and MEL phases accelerates the catalyst deactivation rate.

探明与选择性、稳定性等核心性能参数相关联的催化剂特征，是实现理性催化剂设计的关键所在。本研究聚焦于甲醇制烯烃（methanol-to-olefin, MTO）过程中的构效关系解析，通过对MFI、MEL及其各自共生沸石的催化行为开展细致系统的研究。详尽的材料表征结果证实，丙烯与丁烯的高产率、甲醇（MeOH）高转化能力，均与五硅环（pentasil）结构孔道内晶格铝位点的富集呈显著相关，该结论通过27Al魔角旋转核磁共振（27Al MAS NMR）与3-甲基戊烷裂化实验得到验证。MTO催化性能与其他催化剂特征（如晶体尺寸、外部布伦斯特酸位点（Brønsted acid sites, BAS）的存在、铝配对位点）之间无明显关联，这表明上述因素对丙烯选择性的调控作用并不显著。本研究分析表明，催化剂失活过程较为复杂，其受到孔道交叉位点处晶格铝的富集程度、总铝含量以及晶体尺寸的强烈影响。MFI与MEL相的共生结构会加快催化剂的失活速率。