A defect-based strategy for the preparation of mesoporous zeolite Y for high-performance catalytic cracking

Hydroconversion of Waste Cooking Oil into Green Biofuel over Hierarchical USY-Supported NiMo Catalyst: A Comparative Study of Desilication and Dealumination

“…Thus, with the increase of the mesopores' volume, the crystallinity declined ( Table 1). The formation of the mesopores on the subsurface of the dealuminated USY also reduced the surface acidity (Tables 2 and 3) [26]. Moreover, the catalysts treated by 8% AHFS and 4% NaOH showed the comparable HF values.…”

“…This indicates that the formation of secondary mesopores was closely related to the dealumination method and the mechanism of filling aluminium vacancies by silicon. The silicon insertion rate was too slow to repair the vacancies left by aluminum removal and mesopores formed, and the integrity of the zeolite framework may not be preserved [26]. Thus, with the increase of the mesopores' volume, the crystallinity declined ( Table 1).…”

“…As for the parent USY and desilicated USY zeolites, the framework silicon-to-aluminum ratios determined by X-ray diffraction (XRD) (Si/Al XRD ) was lower than the bulk silicon-to-aluminum ratio determined by XRF, indicating the presence of a large amount of extra-framework silicon [22,25]. This suggests that the extra-framework silicon was easier to remove or part of exfoliated silicon recrystallized in the alkali-treatment [22,25,26].…”

Texture, acidity and fluid catalytic cracking performance of hierarchical faujasite zeolite prepared by an amphiphilic organosilane

“…De Jong and co-workers investigated how steam treatment followed by acid and base leaching steps improves the mesopore interconnectivity, which is useful to limit secondary cracking reactions [27]. The benefit of mesoporosity on the cracking performance of vacuum gas oil and bulky model molecules has been well established [28][29][30][31][32].…”

Flame-Based Synthesis of Core-Shell Structures Using Pd-Ru and Pd Cores

“…A core-shell catalyst's ORR activity is modified because the core material shifts the electronic structure at the surface of the active shell material [1,2]. However, catalytic materials are complex systems in which achieving the desired properties (i.e., activity, selectivity, and stability) depends on exploiting the many degrees of freedom in: surface and bulk composition, geometry, defects, interactions with the support material, control of the reacting environment, and the such, that are currently poorly understood [3][4][5][6][7][8]. Moreover, the local composition and structure of catalytic systems evolve dynamically over a range of time and length scales, [9][10][11][12][13] and are often facilitated by the reacting environment, leading to a loss in the desired properties -a major obstacle that industry fuel cells is the manufacturing cost and price premium for synthesizing the catalyst and then spraying it onto a suitable electrode.…”