The urgent need for sustainable waste management has led to the exploration of upcycling waste plastics and biomass as viable solutions. In 2018, global plastic production reached 359 million tonnes, with an estimated 12000 million tonnes projected to be delivered and disposed of in landfills by 2050. Unfortunately, current waste management practices result in only 19.5% of plastics being recycled, while the rest is either landfilled (55%) or incinerated (25.5%). The improper disposal of plastics contributes to issues such as soil and groundwater contamination, air pollution, and wildlife disturbance. On the other hand, biomass has the potential to deliver around 240 exajoules of energy per year by 2060. However, its current utilization remains relatively small, with only approximately 9% of biomass-derived energy being consumed in Europe in 2017. This review explores various upcycling methods for waste plastics and biomass, including mechanical, chemical, biological, and thermal approaches. It also highlights the applications of upcycled plastics and biomass in sectors such as construction, packaging, energy generation, and chemicals. The environmental and economic benefits of upcycling are emphasized, including the reduction of plastic pollution, preservation of natural resources, carbon footprint reduction, and circular economy advancement.

Exploiting advanced transition metal based electrocatalysts is critical for the oxygen evolution reaction (OER) due to their high efficiency in an alkaline environment for water splitting. Herein, CoS₂ nanosheets were synthesized through simple hydrothermal process and sulfurized layered β-Co(OH)₂ nanosheets as a precursor. The regulation strategy of hexamethylenetetramine was employed to create layered single-crystal β-Co(OH)₂ nanosheets. X-ray absorption fine structure indicates the crystal phase reconstructions occur on β-Co(OH)₂ surface during the sulfidation reaction. The sulfurized β-Co(OH)₂ nanosheets present an overpotential of only 297 mV to reach 10 mA·cm^–2, a low Tafel slope of 71.7 mV·dec^–1 and excellent stability for OER. The results clarified that the CoS₂ nanosheets excellent OER performance is attributable to cobalt sulfide sheet structure and structural changes by sulfur dopants. The results of the sulfurized layered β-Co(OH)₂ to produce CoS₂ nanosheets indicate that this strategy may represents a potential replacement for oxygen evolution application, particularly for the large-scale production of water splitting catalysts.

Regulation of aluminum distribution in zeolite framework is an effective method for improving its catalytic performance for propane aromatization. Herein, we found that recrystallization and post-realuminization of ZSM-5 cannot only create hollow structures to enhance the diffusion ability, but also adjust the content and position of paired aluminum species in its framework. Various characterizations results confirmed that increase of paired aluminum content and inducement of more aluminum atoms sited in the intersection cavity are beneficial to the formation of aromatic products in propane aromatization. As a result, the hollow-structured ZSM-5 zeolite with more paired aluminum (H-200-hollow) showed higher propane conversion and aromatics selectivity than other samples at the same conditions. The catalytic performance of H-200-hollow can be further improved by ion-exchanging with a small amount of Ga(III) species. The propane conversion and aromatics selectivity of Ga-200-hollow reached as high as 95% and 70%, respectively, at 540 °C and 1 atm.

Enhancing nitrogen removal is a very active branch in municipal wastewater treatment research, toward this end, anammox technology is a sustainable solution. This review systematically outlines the strategies employed to enhance mainstream anammox performance, including nitrite accumulation and microbial enrichment based on partial nitrification coupled anammox and partial denitrification coupled anammox, developed to address the challenges of low ammonium content in wastewater, nitrate accumulation in the effluent, and the influence of organic matter. The characteristics and advantages of novel anammox-coupled processes, including partial nitrification and partial denitrification coupled anammox, endogenous partial denitrification coupled anammox, and denitrifying anaerobic methane oxic coupled anammox are also comprehensively discussed; these aim to ensure the highly efficient and stable operation of anammox under diverse wastewater conditions by constructing a composite biological nitrogen removal system based on anammox, supplemented by nitrification-denitrification and other processes. Additionally, a novel anammox application route including mainstream partial denitrification/anammox and absorption-biodegradation as well as sidestream partial nitrification/anammox is proposed, and its application pathway in conceptual wastewater treatment plants is outlined, aiming to foster the development of cost-effective, efficient, and energy-saving advanced wastewater treatment processes. Finally, prospects are presented that indicate the gaps in contemporary research and potential future research directions. Overall, this review provides a reference for treating municipal wastewater with anammox and sheds new light on related strategies and nitrogen removal mechanisms.

Nowadays, global warming caused by the increasing levels of CO₂ has become a serious environmental problem. Membrane separation technology has demonstrated its promising potential in carbon capture due to its easy operation, energy-efficientness and high efficiency. Interfacial polymerization process, as a facile and well-established technique for preparing membranes with a thin selective layer, has been widely used for fabricating commercial reverse osmosis and nanofiltration membranes in water treatment domain. To push forward such an interfacial polymerization process in the research of CO₂ separation membranes, herein we make a review on the regulation and research progress of the interfacial polymerization membranes for CO₂ separation. First, a comprehensive and critical review of the progress in the monomers, nanoparticles and interfacial polymerization process optimization for preparing CO₂ separation membrane is presented. In addition, the potential of molecular dynamics simulation and machine learning in accelerating the screen and design of interfacial polymerization membranes for CO₂ separation are outlined. Finally, the possible challenges and development prospects of CO₂ separation membranes by interfacial polymerization process are proposed. It is believed that this review can offer valuable insights and guidance for the future advancement of interfacial polymerization membranes for CO₂ separation, thereby fostering its development.

Hydrogenolysis has been explored as a promising approach for plastic chemical recycling. Noble metals, such as Ru and Pt, are considered effective catalysts for plastic hydrogenolysis, however, they result in a high yield of low-value gaseous products. In this research, an efficient bimetallic catalyst was developed by separate impregnation of Ni and Ru on SiO₂ support resulting in liquid products yield of up to 83.1 C % under mild reaction conditions, compared to the 65.5 C % yield for the sole noble metal catalyst. The carbon distribution of the liquid products from low density polyethylene hydrogenolysis with Ni-modified catalyst also shifted to a heavier fraction, compared to that with Ru catalyst. Meanwhile, the NiRu catalyst exhibited excellent performance in suppressing the cleavage of the end-chain C–C bond, leading to a methane yield of only 10.4 C %, which was 69% lower than that of the Ru/SiO₂ catalyst. Temperature programmed reduction and desorption of hydrogen and propane were further conducted to reveal the detailed mechanism of low density polyethylene hydrogenolysis over the bimetallic catalyst. The results suggested that the Ni-Ru alloy exhibited stronger H adsorption properties indicating improved hydrogen coverage on the catalyst surface thus enhancing the desorption of reaction intermediates. The carbon number distribution was ultimately skewed toward heavier liquid products.

Unraveling the structure-activity relationship and improving the catalytic performance is paramount in propane dehydro-aromatization reactions. Herein, a tandem catalyst with high propane dehydro-aromatization reaction performance was prepared via coupling the PtFe@S-1 with Zn/ZSM-5 zeolites (PtFe@S-1&1.0Zn/ZSM-5), which exhibits high dehydrogenation activity, aromatics selectivity (~60% at ~78% propane conversion), and stability. The addition of zinc inhibits the cleavage of C₆⁼ intermediates on ZSM-5 and promotes the aromatization pathway by weakening zeolite acid strength, significantly improving the selectivity to aromatics. This understanding of the structure-activity relationship in propane dehydro-aromatization reaction helps develop future high-performance catalysts.

Zeolites, with their exquisite microporous frameworks and tailorable acidities, serve as ubiquitous catalysts across a diverse spectrum of industrial applications, ranging from petroleum and coal processing to sustainable chemistry and environmental remediation. Optimizing their performance hinges on a thorough understanding of the structure-performance relationship. In situ solid-state nuclear magnetic resonance spectroscopy has emerged as a critical tool, providing unparalleled atomic-level insights into both structure and dynamic aspects of zeolite-catalyzed reactions. Herein, we review recent progress in the development and application of the in situ solid-state nuclear magnetic resonance technique to zeolite catalysis. We first review the in situ nuclear magnetic resonance techniques used in zeolite-catalyzed reaction, including batch-like and continuous-flow reaction modes. The conditions and limitations for these techniques are thoroughly summarized. Subsequently, we review the applications of in situ nuclear magnetic resonance techniques in zeolite-catalyzed reaction, focusing on some important catalytic reactions like methanol-to-hydrocarbons, ethanol dehydration, alkane activation, and beyond. Emphasis is placed on the strategies of specific in situ nuclear magnetic resonance methodologies to tackle critical challenges encountered in these fields, such as probing intermediates and unraveling reaction mechanisms. Additionally, we discuss the burgeoning opportunities and prospective challenges associated with in situ nuclear magnetic resonance studies of zeolite-catalyzed processes.

The trend of employing machine learning methods has been increasing to develop promising biocatalysts. Leveraging the experimental findings and simulation data, these methods facilitate enzyme engineering and even the design of new-to-nature enzymes. This review focuses on the application of machine learning methods in the engineering of polyethylene terephthalate (PET) hydrolases, enzymes that have the potential to help address plastic pollution. We introduce an overview of machine learning workflows, useful methods and tools for protein design and engineering, and discuss the recent progress of machine learning-aided PET hydrolase engineering and de novo design of PET hydrolases. Finally, as machine learning in enzyme engineering is still evolving, we foresee that advancements in computational power and quality data resources will considerably increase the use of data-driven approaches in enzyme engineering in the coming decades.

Eucalyptus species are extensively cultivated trees commonly used for timber production, firewood, paper manufacturing, and essential nutrient extraction, while lacking consumption of the leaves increases soil acidity. The objective of this study was to recover bio-oil through microwave pyrolysis of eucalyptus camaldulensis leaves. The effects of microwave power (450, 550, 650, 750, and 850 W), pyrolysis temperature (500, 550, 600, 650, and 700 °C), and silicon carbide amount (10, 25, 40, 55, and 70 g) on the products yields and bio-oil constituents were investigated. The yields of bio-oil, gas, and residue varied within the ranges of 19.8–39.25, 33.75–46.7, and 26.0–33.5 wt %, respectively. The optimal bio-oil yield of 39.25 wt % was achieved at 650 W, 600 °C, and 40 g. The oxygenated derivatives, aromatic compounds, aliphatic hydrocarbons, and phenols constituted 40.24–74.25, 3.25–23.19, 0.3–9.77, and 1.58–7.75 area % of the bio-oils, respectively. Acetic acid (8.17–38.18 area %) was identified as a major bio-oil constituent, and hydrocarbons with carbon numbers C₁ and C₂ were found to be abundant. The experimental results demonstrate the potential of microwave pyrolysis as an eco-friendly and efficient way for converting eucalyptus waste into valuable bio-oil, contributing to the sustainable utilization of biomass resources.

The engineering of microbial cell factories for the production of high-value chemicals from renewable resources presents several challenges, including the optimization of key enzymes, pathway fluxes and metabolic networks. Addressing these challenges involves the development of synthetic auxotrophs, a strategy that links cell growth with enzyme properties or biosynthetic pathways. This linkage allows for the improvement of enzyme properties by in vivo directed enzyme evolution, the enhancement of metabolic pathway fluxes under growth pressure, and remodeling of metabolic networks through directed strain evolution. The advantage of employing synthetic auxotrophs lies in the power of growth-coupled selection, which is not only high-throughput but also labor-saving, greatly simplifying the development of both strains and enzymes. Synthetic auxotrophs play a pivotal role in advancing microbial cell factories, offering benefits from enzyme optimization to the manipulation of metabolic networks within single microbes. Furthermore, this strategy extends to coculture systems, enabling collaboration within microbial communities. This review highlights the recently developed applications of synthetic auxotrophs as microbial cell factories, and discusses future perspectives, aiming to provide a practical guide for growth-coupled models to produce value-added chemicals as part of a sustainable biorefinery.

Reactant gas and liquid water transport phenomena in the flow channels are complex and critical to the performance and durability of polymer electrolyte membrane fuel cells. The polymer membrane needs water at an optimum level for proton conductivity. Water management involves the prevention of dehydration, waterlogging, and the cell’s subsequent performance decline and degradation. This process requires the study and understanding of internal two-phase flows. Different experimental visualization techniques are used to study two-phase flows in polymer electrolyte membrane fuel cells. However, the experiments have limitations in in situ measurements; they are also expensive and time exhaustive. In contrast, numerical modeling is cheaper and faster, providing insights into the complex multiscale processes occurring across the components of the polymer electrolyte membrane fuel cells.

This paper introduces the recent design of flow channels. It reviews the numerical modeling techniques adopted for the transport phenomena therein: the two-fluid, multiphase mixture, volume of fluid, lattice Boltzmann, and pressure drop models. Furthermore, this work describes, compares, and analyses the models’ approaches and reviews the representative results of some selected aspects. Finally, the paper summarizes the modeling perspectives, emphasizing future directions with some recommendations.

Ammonia is a vital component in the fertilizer and chemical industries, as well as serving as a significant carrier of renewable hydrogen energy. Compared with the industry’s principal technique, the Haber-Bosch method, for ammonia synthesis, electro/photocatalytic ammonia synthesis is increasingly recognized as a viable and eco-friendly alternative. This method enables distributed small-scale deployment and can be powered by sustainable renewable energy sources. However, the efficiency of electro/photocatalytic nitrogen reduction reaction is hindered by the challenges in activating the N≡N bond and nitrogen’s low solubility, thereby limiting its large-scale industrial applications. In this review, recent advancements in electro/photocatalytic nitrogen reduction are summarized, encompassing the complex reaction mechanisms, as well as the effective strategies for developing electro/photocatalytic catalysts and advanced reaction systems. Furthermore, the energy efficiency and economic analysis of electro/photocatalytic nitrogen fixation are deeply discussed. Finally, some unsolved challenges and potential opportunities are discussed for the future development of electro/photocatalytic ammonia synthesis.

Direct air capture (DAC) using amine-functionalized solid adsorbents holds promise for achieving negative carbon emissions. In this study, a series of additive-incorporated tetraethylenepentamine-functionalized SiO₂ adsorbents with varying tetraethylenepentamine and additive contents were prepared via a simple impregnation method, characterized by various techniques, and applied in the DAC process. The structure-performance relationship of these adsorbents in DAC was investigated, revealing that the quantity of active amine sites (or the tetraethylenepentamine content in the exposed layer), as determined by CO₂-TPD measurement, was an important factor affecting the adsorbent performance. This factor, which varied with the tetraethylenepentamine content, additive type, and additive content, showed a positive correlation with the CO₂ adsorption capacity of the adsorbents. The optimal adsorbent, 40TEPA-10PEG/SiO₂ containing 40 wt % tetraethylenepentamine and 10 wt % polyethylene glycol (Mn = 200), exhibited a stable CO₂ capacity of 2.1 mmol·g^–1 and amine efficiency of 0.22 over 20 adsorption–desorption cycles (adsorption at 400 ppm CO₂/N₂ and 30 °C for 60 min, and desorption at pure N₂ and 90 °C for 20 min). Moreover, even after deliberate accelerated oxidation treatment (pretreated in air at 100 °C for 10 h), the CO₂ capacity of 40TEPA-10PEG/SiO₂ remained at 2.0 mmol·g^–1. The superior thermal and oxidative stability of 40TEPA-10PEG/SiO₂ makes it a promising adsorbent for DAC applications.

With the rapid iteration and update of wearable flexible devices, high-energy-density flexible lithium-ion batteries are rapidly thriving. Flexibility, energy density, and safety are all important indicators for flexible lithium-ion batteries, which can be determined jointly by material selection and structural design. Here, recent progress on high-energy-density electrode materials and flexible structure designs are discussed. Commercialized electrode materials and the next-generation high-energy-density electrode materials are analyzed in detail. The electrolytes with high safety and excellent flexibility are classified and discussed. The strategies to increase the mass loading of active materials on the electrodes by designing the current collector and electrode structure are discussed with keys of representative works. And the novel configuration structures to enhance the flexibility of batteries are displayed. In the end, it is pointed out that it is necessary to quantify the comprehensive performance of flexible lithium-ion batteries and simultaneously enhance the energy density, flexibility, and safety of batteries for the development of the next-generation high-energy-density flexible lithium-ion batteries.

Triboelectric nanogenerators (TENGs) are among the most promising available energy harvesting methods. Cellulose-based TENGs are flexible, renewable, and degradable. However, the flammability of cellulose prevents it from being used in open-flame environments. In this study, the lattice of cellulose was adjusted by the hydroxyl ionization of cellulose molecules, and Na⁺ was introduced to enhance the flame retardancy of cellulose nanofibers (CNFs). The experimental results showed that the amount of hydrogen bonding between cellulose molecules increased with the introduction of Na⁺ and that the limiting oxygen index reached 36.4%. The lattice spacing of cellulose increased from 0.276 to 0.286 nm, and the change in lattice structure exposed more hydroxyl groups, which changed the polarity of cellulose. The surface potential of the fibers increased from 239 to 323 mV, the maximum open-circuit voltage was 25 V·cm^–2, the short-circuit current was 2.10 μA, and the output power density was 4.56 μW·cm^–2. Compared with those of CNFs, the output voltage, current, and transferred charge increased by 96.8%, 517%, and 23%, respectively, and showed good stability and reliability during cyclic exposure. This study provides a valuable strategy for improving the performance of cellulose-based TENGs.

With the advancement of social process, the resource problem is becoming more prominent, biomass materials come into being, and it is becoming more and more important to explore and prepare efficient and multifunctional biomass materials to alleviate the problems of energy storage and water pollution. In this paper, nitrogen-doped hierarchical porous carbon materials (NRRC) were produced by one-step carbonization of withered rose as raw material and melamine as nitrogen source with KOH-activated porosification. The resulting nitrogen-doped porous carbon material had the most abundant pores and the best microspherical graded pore structure, with a specific surface area of up to 1393 m²·g^–1, a pore volume of 0.68 cm³·g^–1, and a nitrogen-doped content of 5.52%. Electrochemical tests showed that the maximum specific capacitance of NRRC in the three-electrode system was 346.4 F·g^–1 (0.5 A·g^–1), which was combined with favorable capacitance retention performance and cycling stability. The NRRC//NRRC symmetric supercapacitors were further assembled, and the maximum energy density of a single device was 23.88 Wh·kg^–1, which still maintains excellent capacitance retention and cyclic charging/discharging stability. For example, the capacitance retention rate was always close to 96.27% with almost negligible capacitance loss after 10000 consecutive charge/discharge cycles (current density: 10 A·g^–1). Regardless of the three-electrode or two-electrode system, the super capacitive performance of NRRC porous carbon materials was comparable to the electrochemical performance of many reported biomass porous carbon materials, which showed better energy storage advantages and practical application potential. In addition, NRRC porous carbon materials had excellent water purification ability. The dye adsorption test confirmed that NRRC had a high adsorption capacity (491.47 mg·g^–1) for methylene blue. This undoubtedly also showed a potential and promising avenue for high value-added utilization of this material.

In light of the challenges associated with catalyst separation and recovery, as well as the low production efficiency resulting from intermittent operation for titanium silicalite-1 (TS-1) catalyzed phenol hydroxylation to dihydroxybenzene in the slurry bed, researchers keep on exploring the use of a continuous fixed bed to replace the slurry bed process in recent years. This study focuses on preparing a TS-1 coated structured catalyst on SiC foam, which exhibits significant process intensification in performance. We investigated the kinetics of this structured catalyst and compared it with those of extruded TS-1 catalyst; the dynamic equations of the two catalysts were obtained. It was observed that both catalysts followed E-R adsorption mechanism model, with an effective internal diffusion factor ratio between structured and extruded TS-1 of approximately 7.71. It was confirmed that the foamed SiC-based structured TS-1 catalyst exhibited significant improvements in phenol hydroxylation in fixed-bed reactor due to its well-developed pore structure, good thermal conductivity, excellent internal mass transfer performance, and short reactant diffusion distance, leading to higher utilization efficiency of active components. This finding also provides a foundation for designing and developing phenol hydroxylation processes in fixed-bed using structured catalysts through computational fluid dynamics calculations.

The reduced mechanism based on the minimized reaction network method can effectively solve the rigidity problem in the numerical calculation of turbulent internal combustion engine. The optimization of dynamic parameters of the reduced mechanism is the key to reproduce the experimental data. In this work, the experimental data of ignition delay times and laminar flame speeds were taken as the optimization objectives based on the machine-learning model constructed by radial basis function interpolation method, and pre-exponential factors and activation energies of H₂ combustion mechanism were optimized. Compared with the origin mechanism, the performance of the optimized mechanism was significantly improved. The error of ignition delay times and laminar flame speeds was reduced by 24.3% and 26.8%, respectively, with 25% decrease in total mean error. The optimized mechanism was used to predict the ignition delay times, laminar flame speeds and species concentrations of jet stirred reactor, and the predicted results were in good agreement with experimental results. In addition, the differences of the key reactions of the combustion mechanism under specific working conditions were studied by sensitivity analysis. Therefore, the machine-learning model is a tool with broad application prospects to optimize various combustion mechanisms in a wide range of operating conditions.

The oxidative condensation between renewable furfural and fatty alcohols is a crucial avenue for producing high-quality liquid fuels and valuable furan derivatives. The selectivity control in this reaction process remains a significant challenge. Herein, we report the strategy of confining well dispersed gold species within ZSM-5 structure to construct highly active Au@ZSM-5 zeolite catalysts for the oxidative condensation of furfural. Characterization results and spectroscopy analyses demonstrate the efficient encapsulation of isolated and cationic Au clusters in zeolite structure. Au@ZSM-5(K) catalyst shows remarkable performance with 69.7% furfural conversion and 90.2% furan-2-acrolein selectivity as well as good recycle stability. It is revealed that the microstructure of ZSM-5 zeolite can significantly promote oxidative condensation activity through confinement effects. This work presents an explicit example of constructing zeolite encaged noble metal catalysts toward targeted chemical transformations.

Biochar belongs to the category of low-cost, stable, and environmentally benign carbon-based materials. In this article, the reasons that highlight the advantages of biochar materials to be used in carbon dioxide (CO₂) adsorption are briefly viewed with recent examples. Also, the issues to be solved for recommending biochar materials in the practical applications are listed.

Graphene oxide is a promising adsorption material. However, it has been difficult to recycle and separate graphene oxide in the solution. To alleviate this problem, graphene oxide was thermally reduced to produce porous hydrogel which was then functionalized with polydopamine. The functional groups act as not only adsorption sites but also nucleation sites for in situ crystallization of cobalt-doped zeolitic-imidazolate-framework-8 nano-adsorbents. The effects of cobalt-doping contents on the physicochemical and adsorption properties of the resulting aerogel were also evaluated by varying the cobalt concentration. For instance, the reduced graphene oxide-polydopamine/50cobalt-zeolitic-imidazolate-framework-8 aerogel exhibited a high surface area of 900 m²·g^–1 and maintained the structure in water after ten days. The as-synthesized aerogels showed an ultrahigh adsorption capacity of 1217 ± 24.35 mg·g^–1 with a removal efficiency of > 99% of lead, as well as excellent adsorption performance toward other heavy metals, such as copper and cadmium with adsorption capacity of 1163 ± 34.91 and 1059 ± 31.77 mg·g^–1, respectively. More importantly, the lead adsorption stabilized at 1023 ± 20.5 mg·g^–1 with a removal efficiency of > 80% after seven cycles, indicating their potential in heavy metal removal from industrial wastewater.

The dynamics of methanol within prototype methanol synthesis catalysts were studied using quasi-elastic neutron scattering. Three Cu-exchanged zeolites (mordenite, SSZ-13 and ZSM-5) were studied after methanol loading and showed jump diffusion coefficients between 1.04 × 10⁻¹⁰ and 2.59 × 10⁻¹⁰ m²·s^–1. Non-Arrhenius behavior was observed with varying temperature due to methoxy formation at Brønsted acid sites and methanol clustering around copper cations.

This study investigated the interaction between the furfural residue and polyvinyl chloride co-pyrolysis using an infrared heating method. Various analytical techniques including production distribution analysis, thermal behavior, pyrolysis kinetic, simulated distillation and gas chromatography-mass spectrography (GCMS), and X-ray photoelectron spectroscopy were utilized to elucidate the pyrolysis characterization and reaction mechanism during the co-pyrolysis. Initially, the yield of co-pyrolysis oil increased from 35.12% at 5 °C·s^–1 to 37.70% at 10 °C·s^–1, but then decreased to 32.07% at 20 °C·s^–1. Kinetic and thermodynamic parameters suggested non-spontaneous and endothermic behaviors. GCMS analysis revealed that aromatic hydrocarbons, especially mono- and bi-cyclic ones, are the predominant compounds in the oil due to the presence of H radicals in polyvinyl chloride, suggesting an enhancement in oil quality. Meanwhile, the fixed chlorine content increased to 65.11% after co-pyrolysis due to the interaction between inorganic salts in furfural residues and chlorine from polyvinyl chloride.

The traditional separation of bicyclic and tricyclic aromatics from coal tar involves complicated multi-steps and consumes significantly more energy. Previous work accomplished the separation between anthracene-phenanthrene isomers using electrostatic interaction, but for the separation between bicyclic and tricyclic aromatics, electrostatic interactions are difficult to produce a recognizable effect. Naphthalene-based solvents, named as naphthaleneacetamide, naphthaleneethanol, naphthalenemethanol, naphthol, naphthylacetic acid, naphthylacetonitrile, and naphthylamine, respectively, were used for the efficient separation of naphthalene and phenanthrene via dispersion interaction. Results showed that the pre-studied structural parameters are the key factors in selecting an efficient solvent. And the substituents on the intermolecular interactions involved in the separation processes had an important impact, which were evaluated. Naphthalenemethanol exhibited a superior performance with a purity of 96.3 wt % naphthalene products because its electron-donating substituent enables the selective recognition of naphthalene via the dispersion interaction. The used naphthalene-based solvents can be regenerated and recycled via back extraction with a purity of over 90 wt % naphthalene products, suggesting solvent structural stability during the regeneration processes. Notably, the naphthalene-based solvents also demonstrated better separation performance for polycyclic aromatics from coal tar with a purity of over 80 wt % for bicyclic aromatics. This study would enhance the utilization of coal tar as a valuable source of polycyclic aromatics besides broadening the knowledge for applying non-bonded interaction in the separation of polycyclic aromatics technologies.

This study investigates the detailed mechanism of CO₂ conversion to CO using the manganese(I) diimine electrocatalyst [Mn(pyrox)(CO)₃Br], synthesized by Christoph Steinlechner and coworkers. Employing density functional theory calculations, we thoroughly explore the electrocatalytic pathway of CO₂ reduction alongside the competing hydrogen evolution reaction. Our analysis reveals the significant role of diimine nitrogen coordination in enhancing the electron density of the Mn center, thereby favoring both CO₂ reduction and hydrogen evolution reaction thermodynamically. Furthermore, we observe that triethanolamine (TEOA) stabilizes transition states, aiding in CO₂ fixation and reduction. The critical steps influencing the reaction rate involve breaking the MnC(O)–OH bond during CO₂ reduction and cleaving the MnH–H–TEOA bond in the hydrogen evolution reaction. We explain the preference for CO₂ conversion to CO over H₂ evolution due to the higher energy barrier in forming the Mn-H₂ species during H₂ production. Our findings suggest the potential for tuning the electron density of the Mn center to enhance reactivity and selectivity in CO₂ reduction. Additionally, we analyze potential competing reactions, focusing on electrocatalytic processes for CO₂ reduction and evaluating “protonation-first” and “reduction-first” pathways through density functional theory calculations of redox potentials and Gibbs free energies. This analysis indicates the predominance of the “reduction-first” pathway in CO production, especially under high applied potential conditions. Moreover, our research highlights the selectivity of [Mn(pyrox)(CO)₃Br] toward CO production over HCOO^– and H₂ formation, proposing avenues for future research to expand upon these findings by using larger basis sets and exploring additional functionalized ligands.

The oxygen vacancy formation energy and chemical looping dry reforming of methane over metal-substituted CeO₂ (111) are investigated based on density functional theory calculations. The calculated results indicate that among the various metals that can substitute for the Ce atom in the CeO₂(111) surface, Zn substitution results in the lowest oxygen vacancy formation energy. For the activation of CH₄ on CeO₂ (111) and Zn-substituted CeO₂ (111) surfaces, the calculated results illustrate that the dissociation process of CH_3(ads) is very difficult on pristine surfaces and unfavorable for CHO_(ads) on substituted surfaces. Furthermore, the dissociative adsorption of CO and H₂ on the Zn-substituted CeO₂ (111) surface requires high energy, which is unfavorable for syngas production. This work demonstrates that excessive formation of oxygen vacancy can lead to excessively high adsorption energies, thus limiting the conversion efficiency of the reaction intermediates. This finding provides important guidance and application prospects for the design and optimization of oxygen carrier materials, especially in the field of chemical looping dry methane reforming to syngas.

The Fe-Mn bimetallic catalyst is a potential candidate for the conversion of CO₂ into value-added chemicals. The interaction between the two metals plays a significant role in determining the catalytic performance, however which remains controversial. In this study, we aim to investigate the impact of tuning the proximity of Fe-Mn bimetallic catalysts with similar nanoparticle size. And its effect on the physicochemical properties of the catalysts and corresponding performance were investigated. It was found that closer Fe-Mn proximity resulted in enhanced CO₂ hydrogenation activity and inhibited CH₄ formation. The physiochemical properties of prepared catalysts were characterized using X-ray diffraction, H₂ temperature programmed reduction, and X-ray photoelectron spectroscopy, revealing that a closer Fe-Mn distance promoted electron transfer from Mn to Fe, thereby facilitating Fe carburization. The adsorption behavior of CO₂ and the identification of reaction intermediates were analyzed using CO₂-temperature programed desorption and in situ Fourier transform infrared spectroscopy, confirming the intimate Fe-Mn sites contributed to CO₂ adsorption and the formation of HCOO* species, ultimately leading to increased CO₂ conversion and hydrocarbon production. The discovery of a synergistic effect at the intimate Fe-Mn sites in this study provides valuable insights into the relationship between active sites and promoters.

In the present study, a sustainable pretreatment methodology combining liquid hot water and deep eutectic solvent is proposed for the efficient fractionation of hemicellulose, cellulose, and lignin from sugarcane bagasse, thereby facilitating the comprehensive utilization of both C5 and C6 sugars. The application of this combined pretreatment strategy to sugarcane bagasse led to notable enhancements in enzymatic saccharification and subsequent fermentation. Experiment results demonstrate that liquid hot water-deep eutectic solvent pretreatment yielded 85.05 ± 0.66 g·L^–1 of total fermentable sugar (glucose: 60.96 ± 0.21 g·L^–1, xylose: 24.09 ± 0.87 g·L^–1) through enzymatic saccharification of sugarcane bagasse. Furthermore, fermentation of the pretreated sugarcane bagasse hydrolysate yielded 34.33 ± 3.15 g·L^–1 of bioethanol. These findings confirm the effectiveness of liquid hot water-deep eutectic solvent pretreatment in separating lignocellulosic components, thus presenting a sustainable and promising pretreatment method for maximizing the valuable utilization of biomass resources.

The cost-effective separation of ethylene (C₂H₄), ethyne (C₂H₂)_, and ethane (C₂H₆) poses a significant challenge in the contemporary chemical industry. In contrast to the energy-intensive high-pressure cryogenic distillation process, zeolite-based adsorptive separation offers a low-energy alternative. This review provides a concise overview of recent advancements in the adsorptive separation of C₂H₄, C₂H₂, and C₂H₆ using zeolites or zeolite-based adsorbents. It commences with an examination of the industrial significance of these compounds and the associated separation challenges. Subsequently, it systematically examines the utilization of various types of zeolites with diverse cationic species in such separation processes. And then it explores how different zeolitic structures impact adsorption and separation capabilities, considering principles such as cation-π interaction, π-complexation, and steric separation concerning C₂H₄, C₂H₂, and C₂H₆ molecules. Furthermore, it discusses methods to enhance the separation performance of zeolites and zeolite-based adsorbents, encompassing structural design, modifications, and ion exchange processes. Finally, it summarizes current research trends and future directions, highlighting the potential application value of zeolitic materials in the field of C₂H₄, C₂H₂, and C₂H₆ separation and offering recommendations for further investigation.