CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Kaifang Wang,Danlin Chen,Jiali Tang,Zihao Hong,Zhongtai Zhu,Ziyi Yuan,Zhihong Lin,Yuqi Liu,Raphael Semiat,Xuezhong He
Membrane gas separation technologies have emerged as highly prospective avenues for the selective separation of CO 2 . In this research, a novel array of mixed-matrix membranes (MMMs) was engineered, integrating two-dimensional nanosheets of MXene, specifically Ti 3 C 2 T x , into polymers of intrinsic microporosity (PIMs) to selectively separate CO 2 from N 2 . The inclusion of Ti 3 C 2 T x nanosheets, rich in polar functional groups, significantly increases the affinity between CO 2 molecules and the fabricated MMMs. Additionally, the precise modulation of the molecular diffusion channels for CO 2 and N 2 is achievable due to the interlayer spacing between MXene layers (∼0.35 nm) within the PIM-1 matrix. This innovation is predicated on the synergistic effect of solution-diffusion and molecular sieving mechanisms that underpin the gas separation process, leading to a marked improvement in both selectivity for CO 2 over N 2 and the permeability of CO 2 . Among the series, the MMMs with a 0.5 wt% MXene display exceptional separation efficiency, achieving a CO 2 permeability of 12475.3 barrer and a CO 2 /N 2 selectivity of 32.7. Notably, all the PIM-1/MXene membranes prepared with different compositions in this study exceed the Robeson upper bound defined in 2019, indicating their substantial promise for CO 2 separation and capture in industrial applications.
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高影响因子
LANGMUIR
·
2024
·
IF 3.7
Tongguo Huo,Kai Cao,Jianxin Zheng,Dan Zhu,Yuan Lin,Yu Dai,Jian Wu
The mechanism of β-SiC preparation via chemical vapor deposition (CVD) of the SiCl4–CH4–H2–N2 system remains unclear. Consequently, the change of molar Gibbs free energy of the CVD β-SiC chemical reaction in the SiCl4–CH4–H2–N2 system has been studied by the Helsinki Software Corporation (HSC) Chemistry code for the first time. The role of nitrogen in the reaction was confirmed. Seven potential reaction pathways of CVD β-SiC were presented, and the thermodynamic equilibrium components of each reaction were calculated systematically. The most viable reaction pathway and corresponding optimal temperature range for CVD β-SiC were determined. In addition, a kinetic study of CVD β-SiC was conducted. The microscopic morphology and crystal structure of β-SiC coatings prepared on the graphite surface at different temperatures were charactered by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman, etc. Ultimately, through SEM, XRD, and Raman observation, uniform and dense β-SiC coatings with fine grains and high crystallinity were successfully obtained. Furthermore, large β-SiC-coated graphite trays with diameters of 230 and 465 mm were prepared by CVD using the SiCl4–CH4–H2–N2 system, and the average thickness of β-SiC was about 100.6 μm. This study provides a theoretical basis and technical recommendations for the fabrication of SiC-coated graphite trays used in metal–organic chemical vapor deposition (MOCVD) equipment.
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PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
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IF 9
Yang Hong,Yan Zhou,Jiaqi Chen,linqian Qin,Yongqi Li,Yang Li,Hongyan Jiang,Huiyang Zhao,Jinzhu Wu,Xiaohong Wu
Advances in carbon capture and storage (CCS) technologies are critical for mitigating global climate change due to their low cost and operational simplicity. Although zeolites hold promise for carbon capture, the development of advanced zeolite materials with optimized CO 2 separation efficiency and diffusivity remains challenging. In this study, we present a quantum dot-regulated growth strategy, in which silicon quantum dots (SiQDs) act as heterogeneous seeds to not only initiate the growth of nanoscale zeolite units but also guide their assembly. The resulting 13X-SiQDs exhibit a distinct micrometer-scale hollow sphere structure composed of nanoscale zeolite units, which provide additional adsorption sites and mesopores, significantly enhancing adsorption and diffusion. The amino groups on the surface of the SiQDs further enable chemical adsorption with CO 2 , strengthening the binding force. The synergistic combination of thermodynamic and kinetic advantages enables 13X-SiQDs to achieve substantial improvements in CO 2 adsorption capacity (132.20 cm 3 ·g −1 ), CO 2 /N 2 selectivity (561), and diffusion rate. This quantum dot-regulated synthesis strategy offers a promising approach for designing advanced adsorption materials with high performance, extending their potential applications beyond carbon capture.
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LANGMUIR
·
2024
·
IF 3.7
Zhenghao Zhang,Bo Peng,Yupeng Zhang,Jiaxin Xiong,Jingwei Li,Jianwei Liu
A CO2/N2-responsive emulsion provides milder reaction conditions, nontoxicity, and economic feasibility compared to other switchable surfactants. In this study, CO2/N2-responsive pickering emulsions were fabricated by using a compounded dispersion containing SiO2 nanoparticles (NPs) and superamphiphiles as the emulsifying agents. The synergistic effects of the SiO2 NPs and superamphiphiles significantly stabilized the emulsion at all of the tested concentrations and prevented complete phase separation of oil and water. The electrostatic interaction between the SiO2 NPs and superamphiphiles was disrupted after bubbling with CO2 for 30 s, resulting in the breaking of the emulsion. However, the dispersion recovered its interfacial activity after the introduction of N2 and again emulsified the emulsion. This reversible switching behavior was validated through three consecutive cycles of bubbling CO2/N2. The protonation and deprotonation of the SiO2 NPs and superamphiphiles in response to CO2/N2 facilitated reversible assembly and disassembly, which enabled the switching of the emulsions between inactive and active forms. The novel highly stable Pickering emulsions demonstrated rapid demulsification and emulsification in response to CO2/N2 and are promising for a wide range of applications.
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高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
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2024
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IF 8.1
Shaopeng Yu,Ya Liu,Jiangyong Cao,Shibao Wen,ZhenXiu Zhang
The development of efficient and environmentally friendly rubber foams is crucial for reducing fire hazards and protecting lives and property. Herein, this study developed a green microcellular foaming method for lightweight and high-strength chloroprene rubber (CR) flame-retardant foams. A strategy that actively releases H 2 O and rapidly forms carbon to stop flames is proposed by low-toxicity smoke suppression aluminum hydroxide (ATH) and readily carburizable Zinc borate (ZB) as flame retardants. Based on the quantitative information of the cellular structure, the effects of ATH and ZB on the foaming behaviors of CR foams were investigated. Thanks to its excellent compounding effect, a significant increase in the limiting oxygen index up to 36.5 % is achieved with a density of 0.263 g/cm 3 . It also demonstrated excellent smoke suppression with a low total smoke production of 0.19 m 2 , a reduction of 96.6 % compared to pure CR foam. In addition, the incorporation of ATH and ZB effectively improves its mechanical properties and thermal conductivity. This study provides a new path manufacture CR foam with excellent overall performance, which effectively improve the overall safety and energy efficiency of the building.
研究领域:
材料科学
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高分子化学
·
防火材料
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高影响因子
ACS Sustainable Chemistry & Engineering
·
2023
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IF 8.4
Yingshu Wang,Shuyue Wang,Jiasi Gan,Jinni Shen,Zizhong Zhang,Huidong Zheng,Xuxu Wang
One-pot synthesis of urea [(NH2)2CO] from easily available small molecules, that is, N2, CO2, and H2O, is an extremely attractive but very challenging reaction. 2D-CdS@3D-BiOBr composites with S-scheme heterojunctions are constructed via a facile hydrothermal technique followed by a self-assembly method and shown to be an excellent photocatalyst enabling the reduction of N2 and CO2 with H2O to (NH2)2CO under visible light. The optimal 40%2D-CdS@3D-BiOBr sample shows up to 15 μmol·g–1·h–1 total yield of NH3 and (NH2)2CO, of which (NH2)2CO accounts for 54%. The apparent quantum efficiency (AQE) is 3.93% for urea production. On the photocatalyst, urea is speculated to form by two possible chemical routes. One is direct photocatalytic synthesis. Both N2 and CO2 molecules are activated by the Cd2+ ion of 2D-CdS and the oxygen defect of 3D-BiOBr at the edges of the heterojunction interface of 2D-CdS/3D-BiOBr, respectively. *HNCONH* is the key intermediate of the formation of (NH2)2CO molecules. The other is indirect synthesis by photocatalysis and then thermocatalysis. N2 is reduced into NH3 and CO2 is reduced into CO on 2D-CdS by the photogenerated electrons and protons, and then the formed NH3 reacts with the reactant CO2 or the product CO to form (NH2)2CO by thermocatalysis on 2D-CdS. The former is dominant for urea synthesis. The work confirms that urea could be synthesized photocatalytically from cheap N2, CO2, and H2O under visible light. A composite heterojunction semiconductor could be a prospective photocatalyst appropriate for the complex reaction.
研究领域:
材料科学
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环境科学
·
化学工程
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高影响因子
Inorganic Chemistry Frontiers
·
2025
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IF 6.4
Qianyu Chu,Guangmin Ren,Jingdan Zhao,Xiangchao Meng,Jie Meng,Zizhen Li
The photocatalytic nitrogen reduction reaction (NRR) is a sustainable green alternative to the Haber–Bosch process for ammonia production. However, due to the inert properties of dinitrogen, the photocatalytic activity in N2 reduction is still pretty low. Based on density functional theory calculations, this study finds that the formation energy of oxygen vacancies around the V site in InVO4 was significantly lower than that around the In site. This indicated that the V–O bond was thermodynamically less stable and tends to break preferentially. Therefore, selective cleavage of the V–O bond was achieved by subjecting InVO4 to transient high-temperature treatment via rapid Joule heating technology. This resulted in the directed construction of an InVO4-JH catalyst enriched with oxygen vacancies and exposing coordination-unsaturated V sites. The resulting InVO4-JH catalyst delivered a photocatalytic ammonia production rate of up to 35.28 μmol g−1 h−1 under ambient conditions without any sacrificial agent, while exhibiting excellent stability and reaction selectivity. Mechanistic studies and structural characterization confirmed that the formation of oxygen vacancies via V–O bond cleavage releases electrons, which reduce adjacent V5+ to V4+. This created localized electron-rich regions at exposed V sites. Theoretical calculations further confirmed that these exposed V sites act as the active centers of the reaction, not only significantly enhancing nitrogen adsorption but also substantially lowering the energy barrier of the hydrogenation step through alternative reaction pathways. This work provides a novel strategy for the rational design of highly efficient defect-engineered catalysts via targeted bond cleavage.
研究领域:
材料化学
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光催化
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无机化学
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能源化学
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环境催化
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纳米材料
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表面科学
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JOURNAL OF MOLECULAR LIQUIDS
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2020
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IF 5.065
Cheng Yuan,Deng-Jing Chen,Qiu-Xiang Ye,Kai Xiao,Li-Sheng Hao,Yan-Qing Nan
The CO 2 /N 2 -triggered switchable sol–gel transition based on sodium deoxycholate (NaDC) and sodium chloride (NaCl) aqueous solutions has been investigated using both experiments and molecular dynamics (MD) simulations. The effects of CO 2 on the phase behavior, viscosity, pH, electrical conductivity, and microstructure of the NaDC/NaCl mixed system were explored. The mixed system exhibits a recycled CO 2 /N 2 response, and switching between solution state and gel state with six orders of magnitude variation in shear viscosity was achieved within a narrow pH range of 7.82–7.20. The FT-IR and 1 H NMR spectra of the mixed system before and after CO 2 bubbling were measured. The experimental results indicate that NaDC is not directly protonated to deoxycholic acid by the small amount of CO 2 present; instead, an acid salt structure with a strong hydrogen bond , that is, [RCOOH⋯OOCR] − , is formed. MD simulation results reveal that, in the aqueous mixed NaDC/NaCl/CO 2 system, three types of bridging hydrogen bonds between two deoxycholate (DC − ) anions and one H 3 O + or HCO 3 − ion are key factors for the formation of hydrogels. These bridging hydrogen bonds promote the formation of DC − pairs bridged by H 3 O + or HCO 3 − ions (including the acid salt structure) and are beneficial to the growth of micelles and formation of hydrogels. It is worth noting that the bridging hydrogen bond connected by HCO 3 − ions is an aspect of CO 2 -induced hydrogels that distinguishes them from acid-induced hydrogels. In addition, the results indicate that CO 2 and NaCl have a synergistic effect when inducing hydrogel formation. Based on experiments and MD simulations, a CO 2 /N 2 -switchable sol–gel transition mechanism for an aqueous mixed NaDC/NaCl system has been proposed.
研究领域:
化学
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材料科学
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ACS Catalysis
·
2022
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IF 13.7
Biao Hu,Bing-Hao Wang,Lang Chen,Zhang-Jun Bai,Wei Zhou,Jun-Kang Guo,Sheng Shen,Ting-Liang Xie,Chak-Tong Au,Li-Long Jiang,Shuang-Feng Yin
In the design of photocatalysts for ammonia synthesis, the construction of effective nitrogen (N2) adsorption and activation sites is critical. Herein, Fe single atoms were effectively fixed on the surfaces of WO2.72–x nanowires. Electronic interactions between single Fe atoms and WO2.72–x resulted in a d-band center shift toward the Fermi level and thus enhancement of N2 bonding with the catalyst surface. The studies of differential charge density and electron localization reveal that there is enhanced electron transfer from Fe-SA/WO2.72–x to the adsorbed N2, signifying that Fe single atoms are active centers for N2 activation. Benefiting from electronic interactions, the optimized catalyst shows a NH4+ generation rate of 186.5 μmol g–1 h–1 during photocatalytic N2 reduction.
研究领域:
材料科学
·
催化化学
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高影响因子
Catalysts
·
2026
·Vol. 16
·期 8
·689
·
IF 4.5
Zhongqiang Bao,Yiwei Zhang,Zhenhua Ji,Zhenguo Li,Peng Zhang,Ding Luo,Zhanming Chen,Han Gao,Lei Zhu,Hao Chen
Supported Pt catalysts are highly active for the selective catalytic oxidation of ammonia (NH3-SCO), but their practical use is limited by poor N2selectivity and insufficient hydrothermal durability under high-temperature exhaust conditions. Herein, we report a composition-regulated high-entropy oxide interface strategy to stabilize Pt–Cu dual sites and steer NH3oxidation toward selective N2formation. A series of fluorite-type Ce-based high-entropy oxides, including CeZrLaPrYOx, CeSmLaPrYOx, and CeSnLaPrYOx, were constructed as thermally robust supports for Pt and Cu loading. Among them, PtCu/HEO-Zr calcined at 1000 °C exhibits the best NH3-SCO performance, achieving 90% NH3conversion at 260 °C while maintaining N2selectivity above 80% over a broad temperature window of 100–300 °C under a high weight hourly space velocity of 100,000 mL·g−1·h−1. More importantly, after harsh hydrothermal aging at 800 °C with 10 vol% H2O for 12 h, the catalyst shows negligible activity loss and nearly unchanged N2selectivity, demonstrating exceptional structural and catalytic robustness. Structural and surface analyses reveal that Zr incorporation optimizes the fluorite high-entropy lattice, increases oxygen vacancy concentration, promotes lattice oxygen mobility, strengthens surface acidity, and enriches active Cu2+species, thereby enhancing the interfacial cooperation between NH3activation and oxygen-assisted intermediate conversion. In situ DRIFTS further reveals that PtCu/HEO-Zr favors an Olat-assisted internal selective catalytic reduction pathway, in which adsorbed NH3is activated to -NH2species and subsequently reacts with lattice oxygen-derived intermediates to form N2O22−-like species that decompose into N2and H2O. Meanwhile, the formation of nonselective NOxand N2O products is suppressed. This work highlights high-entropy oxide-supported Pt–Cu interfaces as a promising platform for designing hydrothermally durable and N2-selective NH3-SCO catalysts.
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ENERGY & FUELS
·
2026
·
IF 6
Bin Zhou,Yi Zhang,Shugang Li,Zhen Wang,Haifei Lin,Yanlin Chen,Zeyou Meng,Haiqing Shuang,Liang Cheng,Qiqi Yin
The efficient separation of CH4 from binary CH4/N2 mixtures is crucial for utilizing low-concentration coalbed methane but remains a significant challenge. Herein, we systematically investigated the adsorption and separation performance of the metal–organic framework HKUST-1 for CH4, N2, and their mixed gases under different temperatures and pressures. Single-component adsorption experiments revealed that the adsorption capacity of HKUST-1 for CH4 was almost twice that of N2. The adsorption capacity of HKUST-1 for CH4 or N2 is negatively correlated with temperature, and there is a notably higher isosteric heat of adsorption for CH4 than for N2. In addition, grand canonical Monte Carlo (GCMC) simulations confirmed that both CH4 and N2 preferentially occupy the binding sites in T1 pores of HKUST-1 and then migrate to L2 and L3 pores. Differently, CH4 molecules form denser packing at the high-energy metal sites in HKUST-1, while N2 distributes more diffusely. The difference is due to the higher binding energy between CH4 and the Cu node (CH4 is −14.99 kJ/mol, while N2 is −7.83 kJ/mol). Leveraging ideal adsorbed solution theory (IAST) and a breakthrough curve, the superior adsorption selectivity of HKUST-1 for CH4 was evaluated in binary CH4/N2 mixtures. The total adsorption capacity of HKUST-1 for CH4/N2 mixtures is positively correlated with the CH4 concentration, and the adsorption selectivity is better at low CH4 concentrations or low temperatures. Meanwhile, HKUST-1 exhibits good moisture resistance and cycling stability. This research underscores the promise of HKUST-1 for efficient CH4/N2 separation and provides molecular-level insights for next-generation adsorbent design.
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高影响因子
Nature Synthesis
·
2026
·
IF 22.6
Zhang Hao,Liu Ziming,Li Di,Wu Chenxin,Hua Lei,Li Haiyang,Yi Yanhui,Huang Rui,Yu Liang,Deng Dehui
Direct co-conversion of earth-abundant N 2 and CH 4 to high-value C–N–O compounds is a promising synthetic method but remains challenging, as the activation of N 2 and CH 4 typically requires high-energy conditions that can cause product decomposition. Here we report a plasma-cascade process for synthesizing cyclohexanone cyanohydrin (Cy(OH)CN) via direct coupling of N 2 and CH 4 plasma with cyclohexanone. This catalyst-free process achieves a Cy(OH)CN formation rate of 0.60 mmol h −1 with a high selectivity of 95.8% towards the cyclohexanone-derived products under mild conditions, concurrently generating ammonia as a valuable coproduct. Comprehensive mechanistic studies reveal that plasma-generated ·CH x and hydrogen radicals enable direct α-carbonyl functionalization of cyclohexanone to α-CH x cyclohexanol intermediates, which then coupled mainly with excited-state N 2 and are further activated by hydrogen radicals to generate Cy(OH)CN. This plasma-cascade strategy decouples the activation of inert molecules from the formation of relatively unstable C–N–O compounds, enabling selective cyanohydrin synthesis that avoids using high-cost NH 3 and toxic HCN. The alternative text for this image may have been generated using AI.
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