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.

Density functional theory calculations have been performed to examine the different catalytic behaviors of α-Cr 2 O 3 and ZnO in propane dehydrogenation. On ZnO(101̅ 0), adsorption of a Lewis acid at the metal site can be strengthened with the coadsorption of a Lewis base at an adjacent oxygen site. In contrast, this Lewis acid− base interaction does not occur on Cr 2 O 3 (0001) because the Cr ions can exist in a lower oxidation state and thus withdraw electrons from the base, which limits the ability of the oxide to transfer electrons to the acid. Both creating oxygen vacancy and doping single Pt atom on ZnO(101̅ 0) may give rise to a weaker acid−base interaction and hence to a change in the active site. Microkinetic analysis indicates formation of oxygen vacancy has a positive and negative effect on the reactivity of α-Cr 2 O 3 and ZnO, respectively, whereas doping a Pt single atom invariably promotes the dehydrogenation reaction.

Syngas conversion serves as a competitive strategy to produce olefins chemicals from nonpetroleum resources. However, the goal to achieve desirable olefins selectivity with limited undesired C1 by-products remains a grand challenge. Herein, we present a non-classical Fischer-Tropsch to olefins process featuring high carbon efficiency that realizes 80.1% olefins selectivity with ultralow total selectivity of CH4 and CO2 (<5%) at CO conversion of 45.8%. This is enabled by sodium-promoted metallic ruthenium (Ru) nanoparticles with negligible water-gas-shift reactivity. Change in the local electronic structure and the decreased reactivity of chemisorbed H species on Ru surfaces tailor the reaction pathway to favor olefins production. No obvious deactivation is observed within 550 hours and the pellet catalyst also exhibits excellent catalytic performance in a pilot-scale reactor, suggesting promising practical applications.