Resistance to nitrogen-induced catalytic deactivation in VGO cracking: synergistic effect of hierarchical structuring and zeolite Y content in FCC catalysts

Abstract

In this study, four FCC catalysts were synthesized by varying both the zeolite Y content (30 wt% and 40 wt%) and the degree of structural modification through alkaline desilication, aiming to evaluate their resistance to nitrogen-induced catalytic deactivation during the cracking of Colombian vacuum gas oil (VGO). The generation of hierarchical zeolites with intracrystalline mesoporosity enabled their subsequent incorporation into catalyst formulations with different active phase loadings. To simulate severe deactivation conditions, quinoline and indole were added to the VGO as model ni-trogen-containing compounds with distinct basicity. Catalytic performance was assessed in a fixed-bed MAT reactor, analyzing conversion, product distribution and quality, coke deposition, as well as the evolution of textural and acidic properties. The results revealed a synergistic effect between zeolite hierarchization and its loading in the catalyst, leading to enhanced nitrogen tolerance, improved structural stability, and increased resistance to coke-induced deactivation. Specifically, systems containing hierarchical zeolite with higher active phase content exhibited better preservation of Brønsted acidity and reduced coke formation, underscoring the importance of multiscale pore design in mitigating inhibitory effects from nitrogen species. This study provides experimental evidence of the critical role of intracrystalline mesoporosity and zeolite content in determining FCC catalyst performance under severe chemical deactivation scenariosstract text goes here.