Process-separated cascade catalysis for highly efficient alkane-to-aromatic conversion

Bifunctional catalysis is pivotal to industrial heterogeneous catalytic processes, yet its performance is limited by the kinetic entanglement among different elementary steps. In the conversion of light alkanes to aromatics, a promising non-naphtha route to produce benzene, toluene and xylene (BTX) that examples this challenging, this paper describes a process-separated cascade catalysis (PSCC) for efficient BTX synthesis, prioritizing kinetic decoupling over spatial intimacy of active sites in bifunctional systems. We employ a spatially decoupled metal-zeolite catalyst, achieving >95% propane conversion and 82.3% aromatic selectivity with near-exclusive BTX formation at 550 °C during continuous reaction-regeneration cycles. In situ spectroscopies and kinetics analysis reveal that PSCC decouples kinetics of alkane dehydrogenation to olefine intermediates (ethene, propene) in the first stage and synchronizes this process with oligomerization and aromatization reactions in the second stage. This synchronization affords the rate matching of two stage, thus minimizes cracking by-products and enhances BTX production substantially. Combined with high catalytic stability and technoeconomic assessment, this PSCC strategy represents a robust pathway in alkane (C2–C4)-to-BTX conversion and beyond bifunctional catalysis processes. Light alkanes offer a route to key aromatics, but controlling competing catalytic steps remains difficult. This study separates and matches reaction stages to boost benzene, toluene and xylene production.