Restructured zeolites anchoring singly dispersed bimetallic platinum and zinc catalysts for propane dehydrogenation

Pt–Fe Nanoparticles Dispersed on Mesoporous Silica as Selective Catalysts for Dehydrogenation of Isobutane

“…These catalytic results suggest that the presence of coordinatively unsaturated platinum atoms in Pt 1 Fe x (x > 70) clusters/nanoparticles could be responsible for the stable catalytic activity and high stability, as already pointed by other authors in analogous systems with ZnO as a promoter, and attributed to the stabilization of Pt 1 Zn sites (under reaction conditions) with particular resistance to sintering 45,46 or in other Pt 1 M alloys (M = Ga, Fe, Co, and Ni) where the improvement in the performance was attributed to both geometry and electronic effects, 17,47,48 such as the decrease in energy of the unoccupied Pt 5d orbitals, which are main responsible of alkane/alkene adsorption. Leaving aside the scarce formation of coke, the presence of platinum nanocrystals and their subsequent sintering seem to be the most probable cause of deactivation in the monometallic 0.1Pt/SBA-15 catalyst.…”

Enhanced PtIn Catalyst via Ce-Assisted Confinement Effect in Propane Dehydrogenation

“…28,29 Therefore, it is necessary to adopt rational strategies to enhance the structural stability of highly dispersed active sites, examples in our previous works by tuning support-metal interaction, zeolite structure evolution, and confinement. 3,30,31 As the reports of Yang et al, 32 put forward by Hu et al, 33 suitable interface interaction can be beneficial to anchor metal nanoparticles and stimulate the capability to activate reactive molecules. Moreover, the microelectronic structure of the active site is modulated by the change in the physicochemical properties of the carrier surface, which further influences the catalytic performance.…”

“…To date, Pt-based catalysts applied in the PDH field undergo deactivation caused by agglomeration in harsh reaction conditions and regeneration operation. − On the one hand, maintaining a good distribution of active sites is an important means to improve catalytic activity. Nevertheless, the smaller size of the active metal interface with the higher Gibbs surface energy resulted in it readily forming large particles via the Ostwald ripening mechanism or particle migration and coalescence in the reaction process. , Therefore, it is necessary to adopt rational strategies to enhance the structural stability of highly dispersed active sites, examples in our previous works by tuning support-metal interaction, zeolite structure evolution, and confinement. ,, As the reports of Yang et al, the strategy of using S atoms incorporated into the carbon (S–C) carrier and the formed strong chemical Pt–S interaction can help to reduce the free energy of surface-loaded platinum intermetallic nanoparticle, thereby maintaining uniform size distribution and ordered crystal structure at high temperature. Meanwhile, based on the Sabatier principle of antisintering via metal-carrier interaction put forward by Hu et al, suitable interface interaction can be beneficial to anchor metal nanoparticles and stimulate the capability to activate reactive molecules.…”

Synergistic mechanism of isolated Fe3+ and highly dispersed Ptδ+ over zeolite for boosting propane dehydrogenation

“…to modify the Pt active sites via geometric and electronic effects. [16][17][18][19][20][21][22] In addition, since the catalyst supports play a vital role in affecting the Pt dispersity via metalsupport interaction, correspondingly, different supports including Al 2 O 3 , CeO 2 , SiO 2 , MgAl 2 O 4 , carbon materials, and zeolites have been investigated. 6,[23][24][25] Especially, zeolites have been widely investigated as ideal host materials for supported Pt via zeolite pore confinement effect (metal@zeolite), 15,[26][27][28][29] owing to the well-ordered zeolite framework structures, tunable acidity, and superior thermal stability.…”

“…In order to improve the dispersity and stability of Pt active sites, many strategies have been proposed, one effective strategy is to introduce the second metal (Sn, Zn, In, Ga, Mn, Cu, etc.) to modify the Pt active sites via geometric and electronic effects 16–22 . In addition, since the catalyst supports play a vital role in affecting the Pt dispersity via metal‐support interaction, correspondingly, different supports including Al 2 O 3 , CeO 2 , SiO 2 , MgAl 2 O 4 , carbon materials, and zeolites have been investigated 6,23–25 .…”