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1. The effect of strong metal–support interaction (SMSI) on Pt–Ti/SiO ₂ and Pt–Nb/SiO ₂ catalysts for propane dehydrogenation

   https://doi.org/10.1039/d0cy00897d  

   Zhu Chen, Johnny; Gao, Junxian; Probus, Paige R.; Liu, Wei; Wu, Xianli; Wegener, Evan C.; Kropf, A. Jeremy; Zemlyanov, Dmitry; Zhang, Guanghui; Yang, Xin; et al (September 2020, Catalysis Science & Technology)

   null (Ed.)

   In this study, we show how strong metal–support interaction (SMSI) oxides in Pt–Nb/SiO 2 and Pt–Ti/SiO 2 affect the electronic, geometric and catalytic properties for propane dehydrogenation. Transmission electron microscopy (TEM), CO chemisorption, and decrease in the catalytic rates per gram Pt confirm that the Pt nanoparticles were partially covered by the SMSI oxides. X-ray absorption near edge structure (XANES), in situ X-ray photoelectron spectroscopy (XPS), and resonant inelastic X-ray scattering (RIXS) showed little change in the energy of Pt valence orbitals upon interaction with SMSI oxides. The catalytic activity per mol of Pt for ethylene hydrogenation and propane dehydrogenation was lower due to fewer exposed Pt sites, while turnover rates were similar. The SMSI oxides, however, significantly increase the propylene selectivity for the latter reaction compared to Pt/SiO 2 . In the SMSI catalysts, the higher olefin selectivity is suggested to be due to the smaller exposed Pt ensemble sites, which result in suppression of the alkane hydrogenolysis reaction; while the exposed atoms remain active for dehydrogenation. 

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2. Selectivity for ethanol partial oxidation: the unique chemistry of single-atom alloy catalysts on Au, Ag, and Cu(111)

   https://doi.org/10.1039/C9TA04572D  

   Li, Hao; Chai, Wenrui; Henkelman, Graeme (October 2019, Journal of Materials Chemistry A)

   Recently, we found that the atomic ensemble effect is the dominant effect influencing catalysis on surfaces alloyed with strong- and weak-binding elements, determining the activity and selectivity of many reactions on the alloy surface. In this study we design single-atom alloys that possess unique dehydrogenation selectivity towards ethanol (EtOH) partial oxidation, using knowledge of the alloying effects from density functional theory calculations. We found that doping of a strong-binding single-atom element ( e.g. , Ir, Pd, Pt, and Rh) into weak-binding inert close-packed substrates ( e.g. , Au, Ag, and Cu) leads to a highly active and selective initial dehydrogenation at the α-C–H site of adsorbed EtOH. We show that many of these stable single-atom alloy surfaces not only have tunable hydrogen binding, which allows for facile hydrogen desorption, but are also resistant to carbon coking. More importantly, we show that a rational design of the ensemble geometry can tune the selectivity of a catalytic reaction. 

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3. Oxidative dehydrogenation of propane over transition metal sulfides using sulfur as an alternative oxidant

   https://doi.org/10.1039/d0cy01039a  

   Arinaga, Allison M.; Liu, Shanfu; Marks, Tobin J. (October 2020, Catalysis Science & Technology)

   null (Ed.)

   The use of alternative oxidants for the oxidative dehydrogenation of propane (ODHP) is a promising strategy to suppress the facile overoxidation to CO x that occurs with O 2 . Gaseous disulfur (S 2 ) represents a thermodynamically “softer” oxidant that has been underexplored and yet offers a potential route to more selective propylene formation. Here we describe a system for sulfur-ODHP (SODHP). We demonstrate that various metal sulfide catalysts generate unique reaction product distributions, and that propylene selectivities as high as 86% can be achieved at 450–550 °C. For a group of 6 metal sulfide catalysts, apparent activation energies for propylene formation range from 72–134 kJ mol −1 and parallel the corresponding catalyst XPS sulfur binding energies, indicating that M–S bond strength plays a key role in SODHP activity. Kinetic data over a sulfided ZrO 2 catalyst indicate a rate law which is first-order in propane and zero-order in sulfur, suggesting that SODHP may occur via a mechanism analogous to the Mars van Krevelen cycle of traditional ODHP. The present results should motivate further studies of SODHP as a route to the selective and efficient oxidative production of propylene. 

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4. Single-Atom Cobalt Catalysts Coupled with Peroxidase Biocatalysis for C–H Bond Oxidation

   https://doi.org/10.1021/acsami.3c03053  

   Liaqat, Maham; Kankanamage, Rumasha Nipuni; Duan, Hanyi; Shimogawa, Ryuichi; Sun, Jiyu; Nielsen, Monia; Shaaban, Ehab; Zhu, Yuanyuan; Gao, Puxian; Rusling, James F.; et al (August 2023, ACS Applied Materials & Interfaces)

   This paper reports a robust strategy to catalyze in situ C–H oxidation by combining cobalt (Co) single-atom catalysts (SACs) and horseradish peroxidase (HRP). Co SACs were synthesized using the complex of Co phthalocyanine with 3-propanol pyridine at the two axial positions as the Co source to tune the coordination environment of Co by the stepwise removal of axial pyridine moieties under thermal annealing. These structural features of Co sites, as confirmed by infrared and X-ray absorption spectroscopy, were strongly correlated to their reactivity. All Co catalysts synthesized below 300 °C were inactive due to the full coordination of Co sites in octahedral geometry. Increasing the calcination temperature led to an improvement in catalytic activity for reducing O2, although molecular Co species with square planar coordination obtained below 600 °C were less selective to reduce O2 to H2O2 through the two-electron pathway. Co SACs obtained at 800 °C showed superior activity in producing H2O2 with a selectivity of 82–85% in a broad potential range. In situ production of H2O2 was further coupled with HRP to drive the selective C–H bond oxidation in 2-naphthol. Our strategy provides new insights into the design of highly effective, stable SACs for selective C–H bond activation when coupled with natural enzymes. 

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5. Understanding the promotional role of Pd in oxidative alcohol coupling reactions over dilute PdAu alloys

   https://doi.org/10.1016/j.jcat.2025.115942  

   Akinsanya, Oluwatofunmi O; Patel, Deep M; O’Connor, Christopher R; Perich, Marta Perxés; van_der_Hoeven, Jessi ES; Reece, Christian; Roling, Luke T; Eagan, Nathaniel M (March 2025, Journal of Catalysis)

   Oxidative coupling reactions enable biomass-derived oxygenates to serve as sustainable platform molecules for a wide range of high-value chemicals. These catalytic reactions can be selectively triggered over alloys wherein a highly active dopant metal such as Pd is diluted into a sea of highly selective host metal atoms such as Au. Here, a range of supported Pd1Aux (x = 5–200) alloy nanoparticles were synthesized using a sequential reduction method with colloidal Au to achieve a high degree of compositional control and particle size uniformity. The promotional role of Pd was examined in the oxidation of ethanol to yield acetaldehyde and the coupling product ethyl acetate. Reactivity trends indicate that both the overall rate of ethanol oxidation and the selectivity toward coupling increase with Pd doping. Rate order and activation energy trends further suggest that the promotional role of Pd does not likely originate from simple O2 dissociation and spillover but rather from the stabilization of alkoxides at Pd-Au interfaces, disproportionately increasing coupling vs simple oxidation. Infrared spectroscopy and density functional theory calculations offer further insights into Pd microstructures in the presence of various key adsorbates, suggesting that Pd can lend this promotion in an isolated state. While this state is generally unstable in the surface due to preferences for segregation into the bulk, oxygen and pathway intermediates may aid in stabilizing surface structures. These findings lay groundwork to explain selectivity and activity control in a much wider range of oxidative functionalizations and to guide further catalyst development. 

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