Optimizing ZSM-11 Catalysts for Methanol-to-Hydrocarbon Reactions

ZSM-11 (MEL) is an emerging catalyst for a wide variety of applications. The MEL framework is very similar to ZSM-5 (MFI), which is one of the most widely used zeolite catalysts in industry. Recent studies have shown that ZSM-11 has better catalytic performance in several different reactions compared to ZSM-5 [1-3], possibly due to improved intra-crystalline diffusion within the less-tortuous straight channels of the MEL topology. However, there are relatively few systematic studies of ZSM-11 synthesis, specifically with respect to tailored physicochemical properties such as size, shape, and Si/Al ratio (SAR). Here, we will present a systematic study of ZSM-11 catalyst preparation and testing for C1 applications. Through the judicious selection of synthesis parameters, we successfully developed a facile protocol to generate a library of ZSM-11 catalysts with tunable size, shape and SAR. Further optimization of the synthesis process was focused on reducing the use of organic structure-directing agents (OSDAs), which significantly reduced the cost of synthesis. These methods for tailoring zeolite crystallization will be discussed along with catalytic studies using methanol-to-hydrocarbon (MTH) reactions. Collectively, our findings are part of a broader initiative to establish quantitative structure-performance relationships as a platform for optimizing zeolite catalysts.