Fabricating a stable interface of tetracoordinated-phosphorus and framework Al within P-doping ZSM-5 zeolite for catalytic methanol-to-propylene reaction.

Phosphorus (P)-doping H-ZSM-5 zeolites, which is crucial for industrial applications, aim to adjust both acidity and framework stability while optimizing product distribution in heterogeneous catalysis. Nonetheless, current phosphating methods often suffer from inadequate phosphorus dispersion and unclear interfacial interactions with framework aluminum (Al). In this work, P-doping ZSM-5 zeolites were successfully one-step prepared by using tributylphosphine served as an organophosphorus precursor, assisting by density functional theory calculations. On account of this, a stable interface of tetracoordinated-phosphorus and framework Al was fabricated uniformly. Such an interfacial structure not only made more framework Al sit in the straight/sinusoidal channels, but also remodeled Brønsted acid sites and reinforced its acidity. Under comparable conditions, methanol-to-propylene (MTP) evaluations indicated that the high-silica PZ-75 zeolite catalyst displayed an appreciable catalytic lifetime (30 h) and a higher C3H6 selectivity (52.4 %). Additionally, in-situ Fourier transform infrared spectroscopy further revealed that this exceptional MTP performance was attributable to the predominant olefinic pathway and lower hydrogen transfer ability. These results provide valuable information for cognizing phosphorus-zeolite chemistry and creating high-performance MTP catalytic materials.