Systematic Studies of Functional Group Tolerance and Chemoselectivity in Carbene-Mediated Intramolecular Cyclopropanation and Intermolecular C-H Functionalization.

Generating reliable data on functional group compatibility and chemoselectivity is essential for evaluating the practicality of chemical reactions and predicting retrosynthetic routes. In this context, we performed systematic studies using a functional group evaluation kit including 26 kinds of additives to assess the functional group tolerance of carbene-mediated reactions. Our findings revealed that some intermolecular heteroatom-hydrogen insertion reactions proceed faster than intramolecular cyclopropanation reactions. Lewis basic functionalities inhibited rhodium-catalyzed C-H functionalization of indoles. While performing these studies, we observed an unexpected C-H functionalization of a 1-naphthol variant used as an additive.

Freshwater Recovery and Removal of Cesium and Strontium from Radioactive Wastewater by Methane Hydrate Formation.

As human society has advanced, nuclear energy has provided energy security while also offering low carbon emissions and reduced dependence on fossil fuels, whereas nuclear power plants have produced large amounts of radioactive wastewater, which threatens human health and the sustainability of water resources. Here, we demonstrate a hydrate-based desalination (HBD) technology that uses methane as a hydrate former for freshwater recovery and for the removal of radioactive chemicals from wastewater, specifically from Cs- and Sr-containing wastewater. The complete exclusion of radioactive ions from solid methane hydrates was confirmed by a close examination using phase equilibria, spectroscopic investigations, thermal analyses, and theoretical calculations, enabling simultaneous freshwater recovery and the removal of radioactive chemicals from wastewater by the methane hydrate formation process described in this study. More importantly, the proposed HBD technology is applicable to radioactive wastewater containing Cs+ and Sr2+ across a broad concentration range of low percentages to hundreds of parts per million (ppm) and even subppm levels, with high removal efficiency of radioactive chemicals. This study highlights the potential of environmentally sustainable technologies to address the challenges posed by radioactive wastewater generated by nuclear technology, providing new insights for future research and development efforts.

Study on the Relationship between Particulate Methane Monooxygenase and Methanobactin on Gold-Nanoparticles-Modified Electrodes.

(1) Background: Particulate methane monooxygenase (pMMO) has a strong dependence on the natural electron transfer path and is prone to denaturation, which results in its redox activity centers being unable to transfer electrons with bare electrodes directly and making it challenging to observe an electrochemical response; (2) Methods: Using methanobactin (Mb) as the electron transporter between gold electrodes and pMMO, a bionic interface with high biocompatibility and stability was created. The Mb-AuNPs-modified functionalized gold net electrode as a working electrode, the kinetic behaviors of pMMO bioelectrocatalysis, and the effect of Mb on pMMO were analyzed. The CV tests were performed at different scanning rates to obtain electrochemical kinetics parameters. (3) Results: The values of the electron transfer coefficient (α) and electron transfer rate constant (ks) are relatively large in test environments containing only CH4 or O2. In contrast, in the test environment containing both CH4 and O2, the bioelectrocatalysis of pMMO is a two-electron transfer process with a relatively small α and ks; (4) Conclusions: It was inferred that Mb formed the complex with pMMO. More importantly, Mb not only played a role in electron transfer but also in stabilizing the enzyme structure of pMMO and maintaining a specific redox state. Furthermore, the continuous catalytic oxidation of natural substrate methane was realized.

Silver and Gold Complexes with NHC-Ligands Derived from Caffeine: Catalytic and Pharmacological Activity.

N-heterocyclic carbene (NHC) silver(I) and gold(I) complexes have found different applications in various research fields, as in medicinal chemistry for their antiproliferative, anticancer, and antibacterial activity, and in chemistry as innovative and effective catalysts. The possibility of modulating the physicochemical properties, by acting on their ligands and substituents, makes them versatile tools for the development of novel metal-based compounds, mostly as anticancer compounds. As it is known, chemotherapy is commonly adopted for the clinical treatment of different cancers, even though its efficacy is hampered by several factors. Thus, the development of more effective and less toxic drugs is still an urgent need. Herein, we reported the synthesis and characterization of new silver(I) and gold(I) complexes stabilized by caffeine-derived NHC ligands, together with their biological and catalytic activities. Our data highlight the interesting properties of this series as effective catalysts in A3-coupling and hydroamination reactions and as promising anticancer, anti-inflammatory, and antioxidant agents. The ability of these complexes in regulating different pathological aspects, and often co-promoting causes, of cancer makes them ideal leads to be further structurally functionalized and investigated.

Unlocking Diversity: From Simple to Cutting-Edge Synthetic Methodologies of Bis(indolyl)methanes.

From a synthetic perspective, bis(indolyl)methanes have undergone extensive investigation over the past two to three decades owing to their remarkable pharmacological activities, encompassing anticancer, antimicrobial, antioxidant, and antiinflammatory properties. These highly desirable attributes have spurred significant interest within the scientific community, leading to the development of various synthetic strategies that are not only more efficient but also ecofriendly. This synthesis-based literature review delves into the advancements made in the past 5 years, focusing on the synthesis of symmetrical as well as unsymmetrical bis(indolyl)methanes. The review encompasses a wide array of methods, ranging from well-established techniques to more unconventional and innovative approaches. Furthermore, it highlights the exploration of various substrates, encompassing readily available chemicals such as indole, aldehydes/ketones, indolyl methanols, etc. as well as the use of some specific compounds as starting materials to achieve the synthesis of this invaluable molecule. By encapsulating the latest developments in this field, this review provides insights into the expanding horizons of bis(indolyl)methane synthesis.

Metagenomic insights into carbon and nitrogen cycling in the water-land transition zone of inland alkaline wetlands.

Inland alkaline wetlands play a crucial role in maintaining ecological functions. However, these wetlands are becoming more vulnerable to the effects of water level fluctuations caused by global climate change, especially concerning carbon (C) and nitrogen (N) cycling. Here, metagenomics sequencing was used to investigate microorganism diversity, C and N cycling gene abundance at three water level types (D (dry), MF (middle flooded), HF (high flooded)) along an inland alkaline wetland. Our findings reveal that water level was the most important factor in regulating the microbial communities. Distinct shifts in community composition were found along the water level increases, without fundamentally altering their composition. With the increase of water level, the relative abundance of pmoA decreased from 2.5 × 10-5 to 5.1 × 10-6. The C cycling processes shift from predominantly CO2-generated processes under low water levels to CO2 and CH4 co-generated processes under high water levels. The relative abundance of nosZ reached 4.9 × 10-5 in HF, while in D and MF, it is recorded at 4.5 × 10-5 and 3.4 × 10-5, respectively. Water levels accelerate N cycling and generating N2O intermediates. Furthermore, our study highlights the dynamic competition and cooperation between C and N cycling processes. This research provides a comprehensive biological understanding of the influence of varying water levels on soil C and N cycling processes in wetland.

Methane removal efficiencies of biochar-mediated landfill soil cover with reduced depth.

Biochar amendment for landfill soil cover has the potential to enhance methane removal efficiency while minimizing the soil depth. However, there is a lack of information on the response of biochar-mediated soil cover to the changes in configuration and operational parameters during the methane transport and transformation processes. This study constructed three biochar-amended landfill soil covers, with reduced soil depths from 75 cm (C2) to 55 cm (C3) and 45 cm (C4), and the control group (C1) with 75 cm and no biochar. Two operation phases were conducted under two soil moisture contents and three inlet methane fluxes in each phase. The methane removal efficiency increased for all columns along with the increase in methane flux. However, increasing moisture content from 10% to 20% negatively influenced the methane removal efficiency due to mass transfer limitation when at a low inlet methane flux, especially for C1; while this adverse effect could be alleviated by a high flux. Except for the condition with low moisture content and flux combination, C3 showed comparable methane removal efficiency to C2, both dominating over C1. As for C4 with only 45 cm, a high moisture content combined with a high methane flux enabled its methane removal efficiency to be competitive with other soil depths. In addition to the geotechnical reasons for gas transport processes, the evolution in methanotroph community structure (mainly type I methanotrophs) induced by biochar amendment and variations in soil properties supplemented the biological reasons for the varying methane removal efficiencies.

Nickel-based cerium zirconate inorganic complex structures for CO2 valorisation via dry reforming of methane.

The increasing anthropogenic emissions of greenhouse gases (GHG) is encouraging extensive research in CO2 utilisation. Dry reforming of methane (DRM) depicts a viable strategy to convert both CO2 and CH4 into syngas, a worthwhile chemical intermediate. Among the different active phases for DRM, the use of nickel as catalyst is economically favourable, but typically deactivates due to sintering and carbon deposition. The stabilisation of Ni at different loadings in cerium zirconate inorganic complex structures is investigated in this work as strategy to develop robust Ni-based DRM catalysts. XRD and TPR-H2 analyses confirmed the existence of different phases according to the Ni loading in these materials. Besides, superficial Ni is observed as well as the existence of a CeNiO3 perovskite structure. The catalytic activity was tested, proving that 10 wt.% Ni loading is the optimum which maximises conversion. This catalyst was also tested in long-term stability experiments at 600 and 800°C in order to study the potential deactivation issues at two different temperatures. At 600°C, carbon formation is the main cause of catalytic deactivation, whereas a robust stability is shown at 800°C, observing no sintering of the active phase evidencing the success of this strategy rendering a new family of economically appealing CO2 and biogas mixtures upgrading catalysts.

Comparison of different sewage sludge pretreatment technologies for improving sludge solubilization and anaerobic digestion efficiency: A comprehensive review.

Anaerobic digestion (AD) of sewage sludge reduces organic solids and produces methane, but the complex nature of sludge, especially the difficulty in solubilization, limits AD efficiency. Pretreatments, by destroying sludge structure and promoting disintegration and hydrolysis, are valuable strategies to enhance AD performance. There is a plethora of reviews on sludge pretreatments, however, quantitative comparisons from multiple perspectives across different pretreatments remain scarce. This review categorized various pretreatments into three groups: Physical (ultrasonic, microwave, thermal hydrolysis, electric decomposition, and high pressure homogenization), chemical (acid, alkali, Fenton, calcium peroxide, and ozone), and biological (microaeration, exogenous bacteria, and exogenous hydrolase) pretreatments. The optimal conditions of various pretreatments and their impacts on enhancing AD efficiency were summarized; the effects of different pretreatments on microbial community in the AD system were comprehensively compared. The quantitative comparison based on dissolution degree of COD (DDCOD) indicted that the sludge solubilization performance is in the order of physical, chemical, and biological pretreatments, although with each below 40 % DDCOD. Biological pretreatment, particularly microaeration and exogenous bacteria, excel in AD enhancement. Pretreatments alter microbial ecology, favoring Firmicutes and Methanosaeta (acetotrophic methanogens) over Proteobacteria and Methanobacterium (hydrogenotrophic methanogens). Most pretreatments have unfavorable energy and economic outcomes, with electric decomposition and microaeration being exceptions. On the basis of the overview of the above pretreatments, a full energy and economy assessment for sewage sludge treatment was suggested. Finally, challenges associated with sludge pretreatments and AD were analyzed, and future research directions were proposed. This review may broaden comprehension of sludge pretreatments and AD, and provide an objective basis for the selection of sludge pretreatment technologies.

Evaluation of on-site biological treatment options for hydrothermal liquefaction aqueous phase derived from sludge in municipal wastewater treatment plants.

Aerobic treatment, mesophilic anaerobic digestion, thermophilic anaerobic digestion, and dark fermentation were evaluated for on-site biological treatment of municipal sludge derived HTL aqueous. For all four described batch test scenarios, municipal sludge-derived HTL aqueous samples obtained under 290-360 °C and 0-30 min retention time were used. In the aerobic respirometric tests, HTL aqueous samples resulted in a five-day biochemical oxygen demand range of 40.75 g/L (350 °C-25.6 min) to 54 g/L (325 °C-0 min). The calculated aerobic biodegradability index showed that approximately 50 % of the organics in HTL aqueous were easily biodegradable. Mesophilic and thermophilic biochemical methane potential tests resulted in specific yields of 151-179 mL CH4/g chemical oxygen demand (COD) and 103-122 mL CH4/g COD, respectively. HTL aqueous obtained under 360 °C-15 min condition caused total inhibition in both mesophilic and thermophilic anaerobic digestion. Possible causes for this inhibition were pyridine, pyrrolidinone, piperidinone, pyridinol, and phenolic compounds, which were higher in abundance in the 360 °C-15 min sample. HTL aqueous was found unfit for hydrogen production in dark fermentation due to inhibitory composition. In summary, on-site biological treatment of HTL aqueous was found to be most suitable under aerobic and mesophilic anaerobic conditions.

Photocatalytic Activation of Aryl(trifluoromethyl) Diazos to Carbenes for High-Resolution Protein Labeling with Red Light.

State-of-the-art methods in photoproximity labeling center on the targeted generation and capture of short-lived reactive intermediates to provide a snapshot of local protein environments. Diazirines are the current gold standard for high-resolution proximity labeling, generating short-lived aryl(trifluoromethyl) carbenes. Here, we present a method to access aryl(trifluoromethyl) carbenes from a stable diazo source via tissue-penetrable, deep red to near-infrared light (600-800 nm). The operative mechanism of this activation involves Dexter energy transfer from photoexcited osmium(II) photocatalysts to the diazo, thus revealing an aryl(trifluoromethyl) carbene. The labeling preferences of the diazo probe with amino acids are studied, showing high reactivity toward heteroatom-H bonds. Upon the synthesis of a biotinylated diazo probe, labeling studies are conducted on native proteins as well as proteins conjugated to the Os photocatalyst. Finally, we demonstrate that the conjugation of a protein inhibitor to the photocatalyst also enables selective protein labeling in the presence of spectator proteins and achieves specific labeling of a membrane protein on the surface of mammalian cells via a two-antibody photocatalytic system.

Effects of particle size on the pretreatment efficiency and subsequent biogas potential of polylactic acid.

The fragmentation of bioplastics (BPs) before pretreatment and anaerobic digestion is conducted for higher efficiency; however, based on the literature, the size reduction varies widely. In this study, initially, various combinations of thermal-alkaline pretreatments were applied at different strengths to the polylactic acid (PLA) in three groups (<0.5, 0.5 < size < 1.0, and 1.0 < size < 2.0 mm). After pretreatment, the solubilization of PLA was increased to 11.5-40.0 % using alkaline dosage and temperature ranging from 50 to 200 g OH-/kg BP, 60-100 °C, respectively, in a 1-10 h timeframe. The results were statistically proved using a 3D response surface graph, where the pretreatment was more effective for smaller particle sizes. The reduction in particle size also increased the CH4 production, which was more pronounced at the strong pretreatment (24 % increment vs. 10-15 %). Computed results indicated 44-86 % conversion of pretreated PLA particles to CH4, supported by Fourier transform infrared spectroscopy analysis, especially focusing on the intensity of -OH bands.

Manipulating soil microbial community assembly by the cooperation of exogenous bacteria and biochar for establishing an efficient and healthy CH4 biofiltration system.

Manipulating the methanotroph (MOB) composition and microbial diversity is a promising strategy to optimize the methane (CH4) biofiltration efficiency of an engineered landfill cover soil (LCS) system. Inoculating soil with exogenous MOB-rich bacteria and amending soil with biochar show strong manipulating potential, but how the two stimuli interactively shape the microbial community structure and diversity has not been clarified. Therefore, three types of soils with active CH4 activities, including paddy soil, river wetland soil, and LCS were selected for enriching MOB-dominated communities (abbreviated as B_PS, B_RWS, and B_LCS, respectively). They were then inoculated to LCS which was amended with two distinct biochar. Besides the aerobic CH4 oxidation efficiencies, the evolution of the three microbial communities during the MOB enrichment processes and their colonization in two-biochar amended LCS were obtained. During the MOB enriching, a lag phase in CH4 consumption was observed merely for B_LCS. Type II MOB Methylocystis was the primary MOB for both B_PS and B_LCS; while type I MOB dominated for B_RWS and the major species were altered by gas concentrations. Compared to biochar, a more critical role was demonstrated for the bacteria inoculation in determining the community diversity and function of LCS. Instead, biochar modified the community structures by mainly stimulating the dominant MOB but could induce stochastic processes in community assembly, possibly related to its inorganic nutrients. Particularly, combined with biochar advantages, the paddy soil-derived bacteria consortiums with diverse MOB species demonstrated the potent adaption to LCS niches, not only retaining the high CH4-oxidizing capacities but also shaping a community structure with more diverse soil function. The results provided new insights into the optimization of an engineered CH4-mitigation soil system by manipulating the soil microbiomes with the cooperation of exogenous bacteria and biochar.

Integrated CO2 capture and conversion via H2-driven CO2 biomethanation: Cyclic performance and microbial community response.

This study investigated the use of H2-driven CO2 biomethanation for integrated CO2 capture and conversion (iCCC). Anaerobic chambers containing Na2CO3-amended microbial growth medium provided with H2 were inoculated with anaerobic granular sludge. Microorganisms were enriched that could regenerate carbonate by using the bicarbonate formed from CO2 absorption to generate methane. Multiple absorption-regeneration cycles were performed and effective restoration of CO2 absorption capacity and stable carbonate recycling via CO2 biomethanation were observed for CO2 absorbents adjusted to three different pH values (9.0, 9.5, and 10.0). The pH = 10.0 group had the highest CO2 absorption capacity; 65.3 mmol/L in the 5th cycle. A slight alkaline inhibition of acetoclastic methanogenesis occurred near the end of regeneration, but had limited impact on the cyclic performance of the iCCC process. Microbial communities were dominated by H2-utilizing and alkali-tolerant species that could participate in CO2 biomethanation and survive under alternating neutral and alkaline conditions.

Near-infrared reflectance spectroscopy for rapid prediction of biochemical methane potential of wastewater wasted sludge.

The information of biochemical methane potential (BMP) of wasted sludge is essential to ensure the stable operation of sludge management processes. However, conventional anaerobic digestion (AD) approach for BMP test is time-consuming and labour-intensive. Currently, the technique of Near Infrared Spectroscopy (NIRS) is gaining prominence in the biogas production within AD process. Previous studies mostly focused on predicting BMP values for fibrous plant biomass and solid waste, with only a limited number of studies attempting to apply NIRS to obtain BMP values across a wide array of wasted sludge types. To obtain BMP values for this diverse range of wasted sludge efficiently and accurately, it is imperative to develop precise models for assessing BMP values using NIRS. In this study, the possibility of using NIRS to predict the BMP values of wasted sludge was evaluated. A total of 70 sludge samples from different sources were investigated to develop a BMP-prediction model by correlating the measured BMP values with the obtained NIR spectra. As a result, a reliable and successful BMP-prediction model was established with the determination coefficient of 0.90, residual prediction deviation of 3.50 and low root mean square error of prediction of 36.8 mL CH4/g VS. This BMP-prediction model is satisfactory for predicting BMP values of various types of sludge. It could provide support for plant operators to make decisions rapidly, thereby improving the process efficiency and optimizing sludge management procedures.

Roles of the Comproportionation Reaction in SO2 Reduction Using Methane for the Flexible Recovery of Elemental Sulfur or Sulfides.

SO2 reduction with CH4 to produce elemental sulfur (S8) or other sulfides is typically challenging due to high energy barriers and catalyst poisoning by SO2. Herein, we report that a comproportionation reaction (CR) induced by H2S recirculating significantly accelerates the reactions, altering reaction pathways and enabling flexible adjustment of the products from S8 to sulfides. Results show that SO2 can be fully reduced to H2S at a lower temperature of 650 °C, compared to the 800 °C required for the direct reduction (DR), effectively eliminating catalyst poisoning. The kinetic rate constant is significantly improved, with CR at 650 °C exhibiting about 3-fold higher value than DR at 750 °C. Additionally, the apparent activation energy decreases from 128 to 37 kJ/mol with H2S, altering the reaction route. This CR resolves the challenges related to robust sulfur-oxygen bond activation and enhances CH4 dissociation. During the process, the well-dispersed lamellar MoS2 crystallites with Co promoters (CoMoS) act as active species. H2S facilitates the comproportionation reaction, reducing SO2 to a nascent sulfur (Sx*). Subsequently, CH4 efficiently activates CoMoS in the absence of SO2, forming H2S. This shifts the mechanism from Mars-van Krevelen (MvK) in DR to sequential Langmuir-Hinshelwood (L-H) and MvK in CR. Additionally, it mitigates sulfation poisoning through this rapid activation reaction pathway. This unique comproportionation reaction provides a novel strategy for efficient sulfur resource utilization.

Mechanistic manifold in a hemoprotein-catalyzed cyclopropanation reaction with diazoketone.

Hemoproteins have recently emerged as promising biocatalysts for new-to-nature carbene transfer reactions. However, mechanistic understanding of the interplay between productive and unproductive pathways in these processes is limited. Using spectroscopic, structural, and computational methods, we investigate the mechanism of a myoglobin-catalyzed cyclopropanation reaction with diazoketones. These studies shed light on the nature and kinetics of key catalytic steps in this reaction, including the formation of an early heme-bound diazo complex intermediate, the rate-determining nature of carbene formation, and the cyclopropanation mechanism. Our analyses further reveal the existence of a complex mechanistic manifold for this reaction that includes a competing pathway resulting in the formation of an N-bound carbene adduct of the heme cofactor, which was isolated and characterized by X-ray crystallography, UV-Vis, and Mössbauer spectroscopy. This species can regenerate the active biocatalyst, constituting a non-productive, yet non-destructive detour from the main catalytic cycle. These findings offer a valuable framework for both mechanistic analysis and design of hemoprotein-catalyzed carbene transfer reactions.

In Situ Synthesis of Encapsulated Pd@silicalite-2 for Highly Stable Methane Catalytic Combustion.

Methane emissions from vehicles have made a significant contribution to the greenhouse effect, primarily due to its high global warming potential. Supported noble metal catalysts are widely employed in catalytic combustion of methane in vehicles, but they still face challenges such as inadequate low-temperature activity and deactivation due to sintering under harsh operating conditions. In the present work, a series of encapsulated structured catalysts with palladium nanoparticles confined in hydrophobic silicalite-2 were prepared by an in situ synthesis method. Based on various characterization methods, including XRD, HR-TEM, XPS, H2-TPR, O2-TPD, H2O-TPD, CH4-TPR, Raman, and in situ DRIFTS-MS, it was confirmed that PdOx nanoparticles were mainly encapsulated inside the silicalite-2 zeolite, which further maintained the stability of the nanoparticles under harsh conditions. Specifically, the 3Pd@S-2 sample exhibited high catalytic activity for methane oxidation even after harsh hydrothermal aging at 750 °C for 16 h and maintained long-term stability at 400 °C for 130 h during wet methane combustion. In situ Raman spectroscopy has confirmed that PdOx species act as active species for methane oxidation. During this reaction, methane reacts with PdOx to produce CO2 and H2O, while simultaneously reducing PdOx to metallic Pd species, which is further reoxidized by oxygen to replenish the PdOx catalyst.

Unraveling the Valence State and Reactivity of Copper Centers in Membrane-Bound Particulate Methane Monooxygenase.

Particulate methane monooxygenase (pMMO) plays a critical role in catalyzing the conversion of methane to methanol, constituting the initial step in the C1 metabolic pathway within methanotrophic bacteria. However, the membrane-bound pMMO's structure and catalytic mechanism, notably the copper's valence state and genuine active site for methane oxidation, have remained elusive. Based on the recently characterized structure of membrane-bound pMMO, extensive computational studies were conducted to address these long-standing issues. A comprehensive analysis comparing the quantum mechanics/molecular mechanics (QM/MM) molecular dynamics (MD) simulated structures with cryo-EM data indicates that both the CuC and CuD sites tend to stay in the Cu(I) valence state within the membrane environment. Additionally, the concurrent presence of Cu(I) at both CuC and CuD sites leads to the significant reduction of the ligand-binding cavity situated between them, making it less likely to accommodate a reductant molecule such as durohydroquinone (DQH2). Subsequent QM/MM calculations reveal that the CuD(I) site is more reactive than the CuC(I) site in oxygen activation, en route to H2O2 formation and the generation of Cu(II)-O•- species. Finally, our simulations demonstrate that the natural reductant ubiquinol (CoQH2) assumes a productive binding conformation at the CuD(I) site but not at the CuC(I) site. This provides evidence that the true active site of membrane-bound pMMOs may be CuD rather than CuC. These findings clarify pMMO's catalytic mechanism and emphasize the membrane environment's pivotal role in modulating the coordination structure and the activity of copper centers within pMMO.

Metabolic diversity shapes vegetation-enhanced methane oxidation in landfill covers: Multi-omics study of rhizosphere microorganisms.

Vegetation root exudates have the ability to shape soil microbial community structures, thereby enhancing CH4 bio-oxidation capacity in landfill cover systems. In this study, the CH4 oxidation capacity of indigenous vegetation rhizosphere microorganisms within operational landfill covers in Chongqing, China, was investigated for the first time, with the objective of identifying suitable plant candidates for CH4 mitigation initiatives within landfill cover systems. Furthermore, a multi-omics methodology was employed to explore microbial community structures and metabolic variances within the rhizospheric environment of diverse vegetation types. The primary aim was to elucidate the fundamental factors contributing to divergent CH4 oxidation capacities observed in rhizosphere soils. The findings demonstrated that herbaceous vegetation predominated in landfill covers. Notably, Rumex acetosa exhibited the highest CH4 oxidation capacity in the rhizosphere soil, approximately 20 times greater than that in non-rhizosphere soil. Root exudates played a crucial role in inducing the colonization of CH4-oxidizing functional microorganisms in the rhizosphere, subsequently prompting the development of specific metabolic pathways. This process, in turn, enhanced the functional activity of the microorganisms while concurrently bolstering their tolerance to microbial pollutants. Consequently, the addition of substances like Limonexic acid strengthened the CH4 bio-oxidation process, thereby underscoring the suitability of Rumex acetosa and similar vegetation species as preferred choices for landfill cover vegetation restoration.