Optimising the balance between alkene homologation cycle and aromatic hydrocarbon pool cycle (dual cycles) to enhance propylene selectivity, propylene/ethene (P/E) ratio and catalytic stability and unravelling the relationship between the acidity of zeolitic materials and their performance are challenging goals of great importance in state-of-the-art methanol-to-olefin (MTO) research. Hence, in this project, the co-feeding strategy and operating conditions will be used to facilitate control over the balance between dual cycles. The rationale for co-feeding aromatics will be used to shorten the induction period, while alcohols or alkenes are used to enhance the contribution of alkene homologation cycle to influence product selectivities. Moreover, engineered zeolites will be synthesized (tuning acid sites location (straight/sinusoidal channels) and acidic nature (Si/Al ratio or substituted Al by Ta or Ga)) to improve stable operating ranges during MTO with trace co-feeding of aromatics, alcohols or alkenes, aiming for high propylene selectivity (>60%), P/E ratio >8 and catalyst stability of at least 72h in our high-throughput reactor set-up. The identification of zeolite-trapped organics will be characterized by operando FTIR and UV-VIS Diffuse Reflectance Spectroscopic techniques to understand the structure-performance relationship during methanol-to-olefins conversion which will give further information and guidelines for designing next-generation catalyst.