Ga-Doped MgAl₂O₄ Spinel as an Efficient Catalyst for Ethane Dehydrogenation to Ethylene Assisted by CO₂

Abstract

A series of Ga-doped MgAl2O4 spinels was prepared via a simple coprecipitation method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), N2 adsorption, X-ray photoelectron spectroscopy (XPS), and thermogravimetry (TG) techniques. Their acidity and basicity were measured by NH3-temperature-programmed desorption (TPD) and CO2-TPD, respectively. These spinel catalysts exhibit good catalytic performance toward ethane dehydrogenation after Ga-doping either in the absence or in the presence of CO2. Their dehydrogenation activity is positively associated with the amount of surface acid sites of medium-strong strength, confirming that the coordinatively unsaturated Ga3+ cations are the active species in the reaction. The introduction of CO2 shows an obvious promoting effect on the dehydrogenation activity of the catalysts because of their high activity for the reverse water-gas shift reaction along with an improved catalyst stability, as a result of the coexisting Boudouard reaction. An ethane conversion of 43% and ethylene selectivity of 92% can be achieved, and the activity and selectivity of this type of catalysts can be fully recovered by regeneration through calcination in flowing air.

Gallium Metal−Organic Nanoparticles with Albumin-Stabilized and Loaded Graphene for Enhanced Delivery to HCT116 Cells

“…The high-resolution XPS showed peaks at 1143.5 and 1116.5 eV that were assigned to Ga 2p 1/2 and Ga 2p 3/2 , respectively ( Figure 2A and B ), which were consistent with the literature. 50 , 51 In addition, the peaks of 1143.5 and 1116.5 eV were related to the Ga (3d 10 ) species, confirming that the higher oxidation state of gallium as Ga 3+ . The SEM images showed the 2D morphology of BSA/Ga/HBrQ NPs and GO/Ga/HBrQ NPs after freeze-drying ( Figure 2C and D ).…”

Co0−Coδ+ Interface Double‐Site‐Mediated C−C Coupling for the Photothermal Conversion of CO2 into Light Olefins

“…MgAl 2 O 4 (MAO) spinel nanomaterials have been selected as the carrier of active cobalt species due to their stable lattice structure and high-temperature resistance. [14] Cobalt active species were firmly loaded on MAO via an in situ synthesis strategy (Figure 1a). Specifically, the ultrathin nanosheets of β-Co(OH) 2 were synthesized for simultaneous deposition on the MAO support via homogeneous precipitation (Figure S1-S3).…”

“…MgAl 2 O 4 (MAO) spinel nanomaterials have been selected as the carrier of active cobalt species due to their stable lattice structure and high‐temperature resistance [14] . Cobalt active species were firmly loaded on MAO via an in situ synthesis strategy (Figure 1a).…”

Preparation, Structure‐Performance Relationship, and Reaction Network of ZnZSM‐5 for Oxidative Dehydrogenation of Ethane with CO2

“…Previously, oxygen was widely employed for ODH, but due to its strong oxidizability, deep oxidation of C 2 H 6 to CO 2 could hardly be avoided. Therefore, CO 2 , a milder oxidant, was proposed to afford a novel CO 2 ‐ODH process, which showed great promise for the conversion of lower alkanes (mainly C 2 H 6 and C 3 H 8 ) to the corresponding alkenes [5,6] . At the same time, the CO 2 ‐ODH process can also be regarded as a potential strategy of CO 2 utilization that does not need H 2 production in particular, which is very interesting in a carbon neutrality scenario.…”