Probing the Design Rationale of a High‐Performing Faujasitic Zeotype Engineered to have Hierarchical Porosity and Moderated Acidity

Abstract

Porosity and acidity are influential properties in the rational design of solid-acid catalysts.P robing the physicochemical characteristics of an acidic zeotype framework at the molecular level can provide valuable insights in understanding intrinsic reaction pathways,f or affording structure-activity relationships.H erein, we employ av ariety of probe-based techniques (including positron annihilation lifetime spectroscopy(PALS), FTIR and solid-state NMR spectroscopy) to demonstrate howahierarchical design strategy for afaujasitic (FAU)z eotype (synthesized for the first time,v ia as ofttemplating approach,w ith high phase-purity) can be used to simultaneously modify the porosity and modulate the acidity for an industrially significant catalytic process (Beckmann rearrangement). Detailed characterization of hierarchically porous (HP) SAPO-37 reveals enhanced mass-transport characteristics and moderated acidity,w hichl eads to superior catalytic performance and increased resistance to deactivation by coking,c ompared to its microporous counterpart, further vindicating the interplay between porosity and moderated acidity.

Defect-Regulated Frustrated-Lewis-Pair Behavior of Boron Nitride in Ambient Pressure Hydrogen Activation

“…To evaluate the H 2 activation potential of these h-BN materials, their surface basicity and acidity properties were measured by temperature-programmed desorption (TPD) profiles. − As shown in Figure A, no signals were observed in the NH 3 -TPD profiles of h-BN-1 and h-BN-2, indicating there are no active Lewis acid sites in their skeletons. Comparatively, a small peak that appeared at 385 °C, assigned to the unsaturated B centers (Lewis acid sites), was observed in h-BN-3, and the intensity of the corresponding peak significantly increased in the NH 3 -TPD profile of h-BN-4, demonstrating a high content of unsaturated B centers in h-BN-4.…”

Engineering the Framework Cobalt and Hierarchical Pores of Aluminophosphates for Enhanced Performance in n‐Butene Skeletal Isomerization

“…Besides, an additional shared corner was observed between the two peaks (5 and 24 nm), which presents a typical pore connectivity feature of hierarchical porosity. [ 31 ] The detailed textural properties listed in Table S1, Supporting Information further demonstrate the improved mesoporosity and reduced pore length. Both the specific surface areas and mesopore volumes were increased for the mesostructured zeolites compared with the parent samples.…”

Rational Design and Application of Covalent Organic Frameworks for Solar Fuel Production

“…COFs display special characteristics when compared with traditional porous materials such as mesoporous silica [ 28 , 29 ], metal organic frameworks (MOFs) [ 30 ] and zeolites [ 31 , 32 , 33 ]. The tunable porous structure of COFs can display even superior reaction yields in comparison to the other semiconductor based photocatalysts such as graphitic carbon nitride (g-C 3 N 4 ) [ 34 , 35 ].…”