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The development of highly active single‐atom catalysts (SACs) and identifying their intrinsic active sites in oxidizing industrial hazardous hydrocarbons are challenging prospects. Tuning the electronic metal‐support interactions (EMSIs) is valid for modulating the catalytic performance of SACs. We propose that the modulation of the EMSIs in a Pt1−CuO SAC significantly promotes the activity of the catalyst in acetone oxidation. The EMSIs promote charge redistribution through the unified Pt−O−Cu moieties, which modulates the d‐band structure of atomic Pt sites, and strengthens the adsorption and activation of reactants. The positively charged Pt atoms are superior for activating acetone at low temperatures, and the stretched Cu−O bonds facilitate the activation of lattice oxygen atoms to participate in subsequent oxidation. We believe that this work will guide researchers to engineer efficient SACs for application in hydrocarbon oxidation reactions. [ABSTRACT FROM AUTHOR]

Mn3O4, FeMnO x , and FeO x catalysts synthesized via a solvothermal method were employed for catalytic oxidation of methyl-ethyl-ketone (MEK) at low temperature. Mn3O4 with sphere-like morphology exhibited the highest activity for MEK oxidation, over which MEK was completely oxidized to CO2 at 200 °C, and this result can be comparable to typical noble metal loaded catalysts. The activation energy of MEK over Mn3O4 (30.8 kJ/mol) was much lower than that of FeMnO x (41.5 kJ/mol) and FeO x (47.8 kJ/mol). The dominant planes, surface manganese species ratio, surface-absorbed oxygen, and redox capability played important roles in the catalytic activities of catalysts, while no significant correlation was found between specific surface area and MEK removal efficiency. Mn3O4 showed the highest activity, accounting for abundant oxygen vacancies, low content of surface Mn4+ and strong reducibility. The oxidation of MEK to CO2 via an intermediate of diacetyl is a reaction pathway on Mn3O4 catalyst. Due to high efficiency and low cost, sphere-shaped Mn3O4 is a promising catalyst for VOCs abatement. [ABSTRACT FROM AUTHOR]

Effects of nonthermal plasma (NTP) on the selective catalytic reduction of NO by CH (CH-SCR) over Co-In/zeolites were investigated in the presence of SO and HO at low temperatures (

Oxygenated volatile organic compounds (OVOCs), emitted in large quantities by the chemical industry, are a major contributor to the formation of ozone and subsequent particulate matter. For the efficient catalytic oxidation of OVOCs, the challenges of molecular activation and intermediate inhibition remain. The construction of bifunctional active sites with specific structures offers a promising way to overcome these problems. Here, the Pd@Layered-CoO x /MFI bifunctional catalyst with core-shell active sites was rationally fabricated though a two-step ligand pyrolysis method, which exhibits a superb oxidation efficiency toward ethyl acetate (EA). Over this, 13.4% of EA (1000 ppm) can be oxidized at just 140 °C with a reaction rate of 13.85 mmol·g Pd -1 ·s -1 , around 176.7 times higher than that of the conventional Pd-CoO x /MFI catalyst. The electronic coupling of the Pd-Co pair promotes the electron back-donation from Pd nanoparticles to the layered CoO x shell and facilitates the formation of Pd 2+ species, which greatly enhances the adsorption and activation of the electron-rich C═O bond of the EA molecules. In addition, the synergy of these core-shell Pd@Layered-CoO x sites accelerates the activation and transformation of *O species, which inhibit the formation of acetaldehyde and ethanol byproducts, ensuring the rapid total oxidation of EA molecules via the Mars-van Krevelen mechanism. This work established a solid foundation for exploring robust bifunctional catalysts for deep OVOC purification.

The widespread presence of formaldehyde (HCHO) pollutant has aroused significant environmental and health concerns. The catalytic oxidation of HCHO into CO 2 and H 2 O at ambient temperature is regarded as one of the most efficacious and environmentally friendly approaches; to achieve this, however, accelerating the intermediate formate species formation and decomposition remains an ongoing obstacle. Herein, a unique tandem catalytic system with outstanding performance in low-temperature HCHO oxidation is proposed on well-structured Pd/Mn 3 O 4 -MnO catalysts possessing bifunctional catalytic centers. Notably, the optimized tandem catalyst achieves complete oxidation of 100 ppm of HCHO at just 18 °C, much better than the Pd/Mn 3 O 4 (30%) and Pd/MnO (27%) counterparts as well as other physical tandem catalysts. The operando analyses and physical tandem investigations reveal that HCHO is primarily activated to gaseous HCOOH on the surface of Pd/Mn 3 O 4 and subsequently converted to H 2 CO 3 on the Pd/MnO component for deep decomposition. Theoretical studies disclose that Pd/Mn 3 O 4 exhibits a favorable reaction energy barrier for the HCHO → HCOOH step compared to Pd/MnO; while conversely, the HCOOH → H 2 CO 3 step is more facilely accomplished over Pd/MnO. Furthermore, the nanoscale intimacy between two components enhances the mobility of lattice oxygen, thereby facilitating interfacial reconstruction and promoting interaction between active sites of Pd/Mn 3 O 4 and Pd/MnO in local vicinity, which further benefits sustained HCHO tandem catalytic oxidation. The tandem catalysis demonstrated in this work provides a generalizable platform for the future design of well-defined functional catalysts for oxidation reactions.

Light alkanes make up a class of widespread volatile organic compounds (VOCs), bringing great environmental hazards and health concerns. However, the low-temperature catalytic destruction of light alkanes is still a great challenge to settle due to their high reaction inertness and weak polarity. Herein, a Co 3 O 4 sub-nanometer porous sheet (Co 3 O 4 -SPS) was fabricated and comprehensively compared with its bulk counterparts in the catalytic oxidation of C 3 H 8 . Results demonstrated that abundant low-coordinated Co atoms on the Co 3 O 4 -SPS surface boost the activation of adsorbed oxygen and enhance the catalytic activity. Moreover, Co 3 O 4 -SPS has better surface metal properties, which is beneficial to electron transfer between the catalyst surface and the reactant molecules, promoting the interaction between C 3 H 8 molecules and dissociated O atoms and facilitating the activation of C-H bonds. Due to these, Co 3 O 4 -SPS harvests a prominent performance for C 3 H 8 destruction, 100% of which decomposed at 165 °C (apparent activation energy of 49.4 kJ mol -1 ), much better than the bulk Co 3 O 4 (450 °C and 126.9 kJ mol -1 ) and typical noble metal catalysts. Moreover, Co 3 O 4 -SPS also has excellent thermal stability and water resistance. This study deepens the atomic-level insights into the catalytic capacity of Co 3 O 4 -SPS in light alkane purification and provides references for designing efficacious catalysts for thermocatalytic oxidation reactions., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

The development of highly active single-atom catalysts (SACs) and identifying their intrinsic active sites in oxidizing industrial hazardous hydrocarbons are challenging prospects. Tuning the electronic metal-support interactions (EMSIs) is valid for modulating the catalytic performance of SACs. We propose that the modulation of the EMSIs in a Pt 1 -CuO SAC significantly promotes the activity of the catalyst in acetone oxidation. The EMSIs promote charge redistribution through the unified Pt-O-Cu moieties, which modulates the d-band structure of atomic Pt sites, and strengthens the adsorption and activation of reactants. The positively charged Pt atoms are superior for activating acetone at low temperatures, and the stretched Cu-O bonds facilitate the activation of lattice oxygen atoms to participate in subsequent oxidation. We believe that this work will guide researchers to engineer efficient SACs for application in hydrocarbon oxidation reactions., (© 2022 Wiley-VCH GmbH.)

Shape effects of nanocrystal catalysts in different reactions have attracted remarkable attention. In the present work, three types of α-Fe 2 O 3 oxides with different micromorphologies were rationally synthesized via a facile solvothermal method and adopted in deep oxidation of ethane. The physicochemical properties of prepared materials were characterized by XRD, N 2 sorption, FE-SEM, HR-TEM, FTIR, in situ DRIFTS, XPS, Mössbauer spectroscopy, in situ Raman, electron energy loss spectroscopy, and H 2 -TPR. Moreover, the formation energy of oxygen vacancy and surface electronic structure on various crystal faces of α-Fe 2 O 3 were explored by DFT calculations. It is shown that nanosphere-like α-Fe 2 O 3 exhibits much higher ethane destruction activity and reaction stability than nanocube-like α-Fe 2 O 3 and nanorod-like α-Fe 2 O 3 due to larger amounts of oxygen vacancies and lattice defects, which greatly enhance the concentration of reactive oxygen species, oxygen transfer speed, and material redox property. In addition to this, DFT results reveal that nanosphere-like α-Fe 2 O 3 has the lowest formation energy of oxygen vacancy on the (110) facet ( E vo (110) = 1.97 eV) and the strongest adsorption energy for ethane (-0.26 eV) and O 2 (-1.58 eV), which can accelerate the ethane oxidation process. This study has deepened the understanding of the face-dependent activities of α-Fe 2 O 3 in alkane destruction.

Mn 3 O 4 , FeMnO x , and FeO x catalysts synthesized via a solvothermal method were employed for catalytic oxidation of methyl-ethyl-ketone (MEK) at low temperature. Mn 3 O 4 with sphere-like morphology exhibited the highest activity for MEK oxidation, over which MEK was completely oxidized to CO 2 at 200 °C, and this result can be comparable to typical noble metal loaded catalysts. The activation energy of MEK over Mn 3 O 4 (30.8 kJ/mol) was much lower than that of FeMnO x (41.5 kJ/mol) and FeO x (47.8 kJ/mol). The dominant planes, surface manganese species ratio, surface-absorbed oxygen, and redox capability played important roles in the catalytic activities of catalysts, while no significant correlation was found between specific surface area and MEK removal efficiency. Mn 3 O 4 showed the highest activity, accounting for abundant oxygen vacancies, low content of surface Mn 4+ and strong reducibility. The oxidation of MEK to CO 2 via an intermediate of diacetyl is a reaction pathway on Mn 3 O 4 catalyst. Due to high efficiency and low cost, sphere-shaped Mn 3 O 4 is a promising catalyst for VOCs abatement.