Rational Design of Single-Atom-Doped Ga₂O₃ Catalysts for Propane Dehydrogenation: Breaking through Volcano Plot by Lewis Acid–Base Interactions

Abstract

Volcano curves have proven to be particularly useful in new catalyst design in the field of heterogeneous catalysis. On the other hand, the further enhancement of the performance of the optimal catalyst for a given reaction is inherently limited by the Sabatier principle. In this work, microkinetic analysis has been carried out to examine the adsorption and catalytic behaviors of single-atom-doped Ga2O3 catalysts in propane dehydrogenation (PDH), which shows that the volcano-shaped activity plot can be broken through by Lewis acid–base interactions, making it possible to achieve better catalytic performance than that of the most active catalyst lying near the summit of the volcano. The reasoning behind this finding is that the presence of the Lewis acid–base interaction over metal-oxide surfaces may strengthen the coadsorption of a pair of amphoteric species at the M–O site, resulting in distinctly different chemisorption energy and transition state energy scaling relations. As a result, the formation energies of H&H coadsorption at the M–O site and H adsorption on top of O are identified as two different reactivity descriptors in the presence and absence of the Lewis acid–base interaction, respectively, with the resulting activity plots exhibiting a straight-line and a volcano-curve pattern. Further experiments verify that the theoretically predicted catalyst candidate Ir1–Ga2O3 is more effective than the previously reported trace-Pt-promoted Ga2O3 catalyst, which opens up a new way to the rational design of metal-oxide catalysts for the PDH process.

Catalytic Interplay of Ga, Pt, and Ce on the Alumina Surface Enabling High Activity, Selectivity, and Stability in Propane Dehydrogenation

“…The calculations indicated that Pt−O is likely to facilitate the C−H bond activation in propane, whereas Ga− O is responsible for H recombination. 34,35 However, these calculations postulated the atomically dispersed "cationic" Pt on the Ga 2 O 3 surface, which is different from the earlier experimental results indicating the formation of reduced Pt particles under PDH reaction conditions. 29,30 In the present study, the PDH reaction mechanism and catalytic interplay of Ga, Pt, and Ce on the γ-Al 2 O 3 surface are carefully investigated by combining various techniques, including selective poisoning experiments, in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), DFT calculations, and H 2 −D 2 isotope scrambling.…”

“…Recently, density functional theory (DFT) calculations have been performed to understand the catalytic roles of Pt and Ga in Pt-doped Ga 2 O 3 . The calculations indicated that Pt–O is likely to facilitate the C–H bond activation in propane, whereas Ga–O is responsible for H recombination. , However, these calculations postulated the atomically dispersed “cationic” Pt on the Ga 2 O 3 surface, which is different from the earlier experimental results indicating the formation of reduced Pt particles under PDH reaction conditions. , …”

Propylene Synthesis: Recent Advances in the Use of Pt-Based Catalysts for Propane Dehydrogenation Reaction

“…The Pt−O site is more active than the Ga(o)-O site in the propane activation, having a lower activation energy of the rate-limiting step. However, further studies have demonstrated that the Ir 1 −Ga 2 O 3 catalyst is more effective than the Pt-doped Ga 2 O 3 catalyst in PDH reaction [32].…”

Advanced design and development of catalysts in propane dehydrogenation

“…8 Several kinds of materials (Al 2 O 3 , CeO 2 , ZrO 2 , Ga 2 O 3 , SiO 2 , MgAl 2 O 4 /ZnAl 2 O 4 , zeolite, and carbon materials) have been utilized as supports in heterogeneous catalysis of alkane dehydrogenation. [30][31][32][33][34][35][36][37][38] The categories of supports are simply classified as oxides and other materials.…”

“…37 Chang et al carried out a microscopic dynamic analysis of a single atom doped Ga 2 O 3 catalyst, achieving an important breakthrough with volcano-like plots, which can be attributed to the interaction originating from Lewis acid-base effects. 38 Deng and colleagues synthesized a precursor material through a wet impregnation method and then modified it with Pt nanoparticles, which acted as the major active center by a direct H 2 reduction pathway. 47 The authors claimed that the superior performance with a conversion of 21.3% and a selectivity of 94.4% is mainly attributed to the SMSI effect between the support and active center.…”