Catalytic non-oxidative direct dehydrogenation of light alkanes serves as an effective reinforcement to selectively produce the corresponding olefins, and the heterogeneous metals and metal oxides, not limited to the commercially used Pt- and Cr-based catalysts, are widely investigated to enhance the efficiency. In this review, we outline the progress of these dehydrogenation catalysts that have been mainly developed in the past five years. For different classes of the most-promising catalysts in the selective dehydrogenation of ethane-to-ethylene and propane-to-propylene, their syntheses, structural information, catalytic properties and mechanisms are comparatively summarized.

Recent progress in heterogeneous metal and metal oxide catalysts for direct dehydrogenation of ethane and propane

Novel montmorillonite-nanosheet/chitosan (MMTNS/CS) hydrogels fabricated via the self-assembly of exfoliated MMTNS and CS chains were investigated. The exfoliation of MMTNS, self-assembly mechanism and structure of MMTNS/CS hydrogels were characterized by an atomic force microscope, scanning electron microscope, transmission electron microscope, Fourier transform infrared spectroscope, energy-dispersive x-ray spectroscope and Brunauer-Emmett-Teller analyzer, respectively. The results indicated that MMT could be easily exfoliated to nanosheets with a thickness of 1 ∼ 5 nm in aqueous solution by an ultrasonic base upon interlayer hydration. The formation mechanism of the self-assembly hydrogels was due to the hydrogen bond (-OH ··· +NH3-) and electrostatic interaction between the MMTNS and CS. The MMTNSs were connected consecutively by CS in-plane to form a huge slice. The porous structure of the hydrogels was controllable by adjusting the MMTNS/CS mass ratio. The hydrogels could be used as adsorbents for sewage treatments, carriers for drugs, microorganisms and catalyzers due to their controllable porous structure and tremendous specific surface area which were derived from the completely exfoliated MMTNS.

https://iopscience.iop.org/article/10.1088/1361-6528/aa9ba4/pdf

Preparation and characterization of self-assembly hydrogels with exfoliated montmorillonite nanosheets and chitosan.

Dehydrogenation of methylcyclohexane over PtSn supported on MgAl mixed metal oxides derived from layered double hydroxides

Fabrication of highly dispersed Pt-based catalysts on γ-Al2O3 supported perovskite Nano islands: High durability and tolerance to coke deposition in propane dehydrogenation

Enhanced catalytic performance of PtSn catalysts for propane dehydrogenation by a Zn-modified Mg(Al)O support

Facile preparation of PtSn-La/Al2O3 catalyst with large pore size and its improved catalytic performance for isobutane dehydrogenation

Carbon-doped alumina (CDA) beads with different carbon contents were prepared by an ammonium alginate (ALG) assisted sol–gel method via changing the concentration of ALG in preparation process, which were used as the support of Pt–Sn–K catalysts. XRF, XRD, BET, TEM, EDS, NH3-TPD, TG and Raman techniques were employed to characterize the physical–chemical properties of CDA materials and Pt–Sn–K catalysts. Results showed that the as-prepared CDA materials all contained carbon and the carbon content was positively correlated with the concentration of ALG used in preparation process. The addition of carbon improved obviously the activity and stability of catalysts in propane dehydrogenation reaction due to larger specific surface (> 320 m2/g), more weak and moderate acid sites and strong resistance to carbon deposition. The PtSnK/CDA-1.5 with the optimal carbon content of 2.6 wt% exhibited the best activity and stability, for which the propane conversion was just declined from 36.4 to 28.7% and the propene selectivity remained above 96.7% even after the reaction for 106 h.

Gong-bing Yang

Papers

Facile preparation of PtSn-La/Al2O3 catalyst with large pore size and its improved catalytic performance for isobutane dehydrogenation

Preparation of carbon-doped alumina beads and their application as the supports of Pt–Sn–K catalysts for the dehydrogenation of propane