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Developing efficacious catalysts with superior Cl resistance and polychlorinated byproduct inhibition capability is crucial for realizing the environmentally friendly purification of chlorinated volatile organic compounds (CVOCs). Activating CVOC molecules and desorbing Cl species by modulating the metal–oxygen property is a promising strategy to fulfill these. Herein, a bifunctional CoRu/Al2O3catalyst with synergistic Co and Ru interactions (Ru–O–Co species) was rationally fabricated, which possesses abundant surface Co2+and Ruδ+sites and collaboratively facilitates the activation of lattice oxygen (O2–) and molecular oxygen (O2→ O2–→ O–), accelerating 1,2-dichloroethane (1,2-DCE) decomposition viathe reaction route of enolic species → aldehydes → carboxylate/carbonate. Furthermore, CoRu/Al2O3stimulates 1,2-DCE oxidation under humid conditions as H2O molecules can be easily activated to active *OH (potential oxidizing agent) over Ru species, accelerating C–Cl dissociation and Cl desorption and promoting the transformation of catecholate-type (C═O) species to easily oxidizable carboxylic acid (COOH) species, remarkably suppressing the formation of hazardous CCl4and CHCl2CH2Cl. This study provides critical insights into the development of bifunctional catalysts to synergistically activate surface oxygen species and H2O molecules for industrial CVOC stable and efficient elimination.

Catalytic purification of industrial oxygenated volatile organic compounds (OVOCs) is hindered by the presence of water vapor that attacks the active sites of conventional noble metal-based catalysts and the insufficient mineralization that leads to the generation of hazardous intermediates. Developing catalysts simultaneously with excellent water resistance and a high intermediate suppression ability is still a great challenge. Herein, we proposed a simple strategy to synthesize a Pd/CoOOH catalyst that contains abundant hydroxyl groups and lattice oxygen species, over which a negligible effect was observed on CH3OH conversion with 3 vol % water vapor, while a remarkable conversion reduction of 24% was observed over Pd/Co3O4. Moreover, the low-temperature CO2selectivity over Pd/CoOOH is significantly enhanced in comparison with Pd/Co(OH)2. The high concentration of surface hydroxyl groups on Pd/CoOOH enhances the water resistance owing to the accelerated activation of H2O to generate Co–OH, which replaces the consumed hydroxyl and facilitates the quick dissociation of surface H2O through timely desorption. Additionally, the presence of Pd–Olatt–Co promotes electron transport from Co to Pd, leading to improved metal–support interactions and weakened metal–O bonds. This in turn enhances the catalyst’s capacity to efficaciously convert intermediates. This study sheds new insights into designing multifunctional catalytic platforms for efficient industrial OVOC purification as well as other heterogeneous oxidation reactions.

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-CoOx/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·gPd–1·s–1, around 176.7 times higher than that of the conventional Pd-CoOx/MFI catalyst. The electronic coupling of the Pd–Co pair promotes the electron back-donation from Pd nanoparticles to the layered CoOxshell and facilitates the formation of Pd2+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-CoOxsites 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 viathe Mars–van Krevelen mechanism. This work established a solid foundation for exploring robust bifunctional catalysts for deep OVOC purification.

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 Co3O4sub-nanometer porous sheet (Co3O4-SPS) was fabricated and comprehensively compared with its bulk counterparts in the catalytic oxidation of C3H8. Results demonstrated that abundant low-coordinated Co atoms on the Co3O4-SPS surface boost the activation of adsorbed oxygen and enhance the catalytic activity. Moreover, Co3O4-SPS has better surface metal properties, which is beneficial to electron transfer between the catalyst surface and the reactant molecules, promoting the interaction between C3H8molecules and dissociated O atoms and facilitating the activation of C–H bonds. Due to these, Co3O4-SPS harvests a prominent performance for C3H8destruction, 100% of which decomposed at 165 °C (apparent activation energy of 49.4 kJ mol–1), much better than the bulk Co3O4(450 °C and 126.9 kJ mol–1) and typical noble metal catalysts. Moreover, Co3O4-SPS also has excellent thermal stability and water resistance. This study deepens the atomic-level insights into the catalytic capacity of Co3O4-SPS in light alkane purification and provides references for designing efficacious catalysts for thermocatalytic oxidation reactions.

Achieving excellent efficiency to mineralize volatile organic compounds (VOCs) under nonthermal plasma catalysis (NTP-catalysis) systems tremendously relies on the catalyst design. Herein, we report a dual-template strategy for synthesizing a core–shell structured nitrogen-enriched hollow hybrid carbon (N-HHC) by a facile pyrolysis of a Mn-ZIF-8@polydopamine core–shell precursor. N-HHC exhibits a remarkable plasma synergy effect and superior degradation efficiency for toluene (up to 90% with a specific input energy of 281 J/L), excellent CO2selectivity (>45%), and byproduct-inhibiting capability. Such outstanding functionality of the developed N-HHC is uniquely attributed to its hollow multistage and channeling structure, high concentration of O3-decomposing species (pyrrolic and oxide pyridinic-N), and abundant ZnO active sites. Shedding light on an efficient synthetic strategy for designing an advanced nanocatalyst with enhanced VOC destruction in the NTP-catalysis system, the present results could be extended to design other N-doped metal/metal oxide-decorated hollow porous carbons for environment-related applications.

It is of great significance to design highly active and stable catalysts for CO oxidation. Herein, a Pt/In–SnO2catalyst was firstly fabricated viaa facile hydrothermal reaction coupled with photoreduction strategy, achieving 1 vol% of CO totally oxidized at just 145 °C, over 200 °C lower than that of Pt/SnO2. Moreover, Pt/In–SnO2demonstrates superior catalytic stability and recyclability under both dry and humid conditions. Incorporation of In cations results in marked structure distortion of SnO2, promoting the formation of oxygen vacancies and enhancing the concentration and mobility of reactive oxygen species. Abundant Pt sites over Pt/In–SnO2further accelerate CO adsorption and activation. Density functional theory results prove that the energy barrier of CO oxidation reduces from 0.85 to 0.75 eV after In doping and the produced CO2can desorb spontaneously from the catalyst surface, which accelerates the CO oxidation process. This work provides new ideas for designing robust catalysts for low-temperature CO elimination.

The alkali metal potassium has the functions of structure promotion and electronic modulation in metal oxides. Herein, diverse potassium precursors (KOH, KNO3, K2SO4, and KCl) were introduced to α-MnO2nanorods through a facile post-processing strategy. The presence of potassium species has a remarkable promotion effect on the catalytic performance of α-MnO2. Amongst them, the KOH/MnO2sample has the highest activity and can destroy 90% toluene (1000 ppm) at just 226 °C with a reaction rate of 3.39 × 10−4mol gcat−1s−1, which is over 20 times higher than that of pure α-MnO2. Different anions in the potassium precursors bring a distinct mutation in the α-MnO2structure, promote the formation of MnO6–K–MnO6bridging bonds in α-MnO2, and exhibit obvious diverse abilities for balancing charge transfer. KOH is identified as the most promising precursor for alkali metal modification, which significantly improves the distribution of K species over the α-MnO2surface and strengthens the content and activity of lattice oxygen. It is confirmed that the lattice oxygen plays a key role in the catalytic oxidation of toluene over α-MnO2, which follows the Mars–van Krevelen mechanism. Positive hole defects (Mn3+) caused by KOH treatment play an important role in the diffusion of O and enhance the reducibility of manganese oxide. In addition, the enhanced specific surface area, pore volume, and surface acidity are also conducive for the catalytic oxidation of toluene.

Pt/Eu2O3-CeO2materials with different Eu concentrations were prepared and applied to toluene destruction, and the remarkable promotion impact of EuOxon Pt/CeO2can be observed. The characterization results reveal that the presence of EuOxsignificantly enhances the redox property, lattice O concentration, and Ce3+ratio of the Pt/CeO2material, which facilitates the dispersion and activity of Pt active sites and thus accelerates the decomposition process of toluene. Among all catalysts, a sample with an Eu content of 2.5 at.% (Pt/EC-2.5) possesses the best catalytic activity with 0.09 vol% of toluene completely destructed at 200 °C under a relatively high GHSV of 50000 h−1. The possible reaction pathway and mechanism of toluene combustion over Pt/Eu2O3-CeO2samples are presented according to in-situDRIFTS, which confirms that the toluene oxidation process obeys the Mars-van Krevelen mechanism with aldehydes and ketones as primary organic intermediates.

Shape effects of nanocrystal catalysts in different reactions have attracted remarkable attention. In the present work, three types of α-Fe2O3oxides 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, N2sorption, FE-SEM, HR-TEM, FTIR, in situ DRIFTS, XPS, Mössbauer spectroscopy, in situ Raman, electron energy loss spectroscopy, and H2-TPR. Moreover, the formation energy of oxygen vacancy and surface electronic structure on various crystal faces of α-Fe2O3were explored by DFT calculations. It is shown that nanosphere-like α-Fe2O3exhibits much higher ethane destruction activity and reaction stability than nanocube-like α-Fe2O3and nanorod-like α-Fe2O3due 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-Fe2O3has the lowest formation energy of oxygen vacancy on the (110) facet (Evo(110) = 1.97 eV) and the strongest adsorption energy for ethane (−0.26 eV) and O2(−1.58 eV), which can accelerate the ethane oxidation process. This study has deepened the understanding of the face-dependent activities of α-Fe2O3in alkane destruction.