Operando XRD analysis of novel zeolite-based methanol-to-olefins catalysts

Methanol-to-olefins (MTO) process is an effective method to produce light olefins such as propylene. Recently we have discovered unusual propylene selectivity over Ca-containing zeolite catalysts. We assume that the interaction between Ca2+-cites and hydrocarbons occurs in a non-trivial way greatly affecting the MTO mechanism. However, the exact mechanisms behind destabilization of coke precursors and improvement of propylene selectivity remain poorly understood. Here we propose to perform operando XRD measurements at ID31 beamline. With the aid of operando XRD study, we expect to elucidate the difference in the zeolite unit cell parameters during the methanol-to-olefins reaction over Ca/ZSM-5 catalysts, and correlate the change with gradual increase of hydrocarbons retained. The experiment will allow us to link the hydrocarbons evolution to the structural properties of the catalyst simultaneously providing comprehensive understanding to reveal the catalyst deactivation mechanism.