SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Lijie Fu,Juanjuan Gong,Hengyu Li,Jinhua Xiao,Bihong Lv,Xiaomin Wu,Zhiwei Huang,Zuoming Zhou,Guohua Jing
The regeneration of catalytic amine-based solvents using solid acid offers a promising approach to reduce energy consumption in CO 2 capture processes. Nickel-based solid acid catalysts, endowed with multiple Lewis acid sites, could enhance the efficiency of regeneration reactions. Nevertheless, the irregular pore structure of NiO and the deficiency in Brønsted acid sites posed significant challenges to the practical use of amine solvent regeneration in CO 2 vapor stripping processes. A highly effective solid acid catalyst, nickel-modified H-β (Ni/β), were synthesized to enhance CO 2 desorption from MEA solutions saturated with CO 2 . The catalyst with 1.25% Ni (1.25% Ni/β) exhibited the highest activity and stability, with a 43.19% increase in the amount of desorbed CO 2 and a 30.16% reduction in relative heat duty. The catalyst maintained excellent stability, enhancing the desorption performance of MEA after ten cyclic absorption–desorption experiments. According to theoretic calculations and experimental analyses, the incorporation of H-β zeolite significantly enhanced the specific surface area of the composite and introduced a substantial number of Brønsted acid sites. Concurrently, the introduction of metal nickel substituted the hydrogen proton on the hydroxyl groups of the H-β molecular sieve, increasing the Lewis acid sites and modulating the Brønsted-to-Lewis acid site ratio. The Brønsted acid sites functioned as proton donors, while the Lewis acid sites facilitated N-C bond cleavage, promoting carbamate decomposition and the deprotonation of protonated amines. This work presents a valuable solid acid catalyst for amine-based CO 2 capture and offers insights for developing innovative solid acids for various catalytic processes.
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高影响因子
Molecular Catalysis
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2025
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IF 4.9
Shengxin An,Shuaibo Zhao,Jingting Jin,Tao He,Yuhao Wang,Na Kong,Jie Zhou,Wenzhi Li
Great expectations have been placed on bimetallic co-modified zeolite for the direct oxidation of methane to methanol. In this work, H-ZSM-5 zeolite was modified with bimetallic copper and zinc via ion-exchange method. Numerous experiments were conducted and the methanol yield of 44,302.70 μmol·g cat −1 ·h −1 was obtained over 1Cu/2Zn-ZSM-5 catalyst. A series of characterization analyses confirmed that the introduction of Zn increased the proportion of active Cu species bound to extra-framework oxygen by altering the electronic state of copper. The bis (μ-oxo) dicopper ligand was identified as the active site for methane oxidation. The possible reasonable reaction pathway was the free radical reaction. This work provides a valuable guidance for the preparation of co-modified zeolite catalysts for the direct oxidation of methane to methanol.
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FUEL
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2024
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IF 6.7
Mei Ren,Jun Li,Manhong Huang,Donghui Chen,Xuelian Chen,Qi An,Songmei Sun
The escalating environmental issues resulting from waste plastic necessitate innovative decomposition methods that optimize conversion rates and product selectivity. In this study, we demonstrate that linear low-density polyethylene (LLDPE) can be effectively hydrothermolyzed into C1 − C4 compounds with a selectivity of 100 % in the presence of trace water on H-ZSM-5 catalyst under a relatively low temperature of 220 °C. Water plays a dual role here as both a solvent and a reactant. It was found the density of Brønsted acid sites is crucial for LLDPE decomposition, serving as the primary active centers for cracking LLDPE chains. In-situ EPR studies indicate a synergistic mechanism of free radical and carbenium ion pathways in LLDPE depolymerization. Density Functional Theory (DFT) simulations show that the depolymerization starts with the cleavage of a C–C bond in polyethylene, instigated by a hydrogen radical from the Brønsted acid site, leading to various intermediate stages for the formation of tert -butanol, acetone and acetic acid from two potential pathways. The presence of water is crucial in these pathways, aiding bond breakages and the creation of oxygenated products in the Brønsted acid site. This study represents a substantial leap forward in sustainable methodologies for upcycling plastic waste.
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CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Lu Liu,Yajie Chen,Jiajia Zhang,Fanze Zeng,Jinyu Bao,Wenpeng Li,Guohui Tian
The rational construction of heterojunctions with surface defects and localized surface plasmon resonance (LSPR) effect is a promising strategy for improving CO 2 photoreduction performance. Herein, the one-dimensional/two-dimensional (1D/2D) S-scheme heterostructures integrated with non-stoichiometric 1D W 18 O 49 nanowires (H-W 18 O 49 NWs) and 2D ultrathin MIL-125(Ti) nanosheets (MIL-125(Ti) NSs) were constructed by self-assembly for photocatalytic CO 2 reduction. In situ X-ray photoelectron spectroscopy (XPS), electron spin resonance spectra (ESR), and photoluminescence (PL) spectroscopy characterizations confirm the construction of S-scheme heterojunction and the solid internal electric field at the heterointerface enables effective spatial charge separation while keeping a strong redox capability. The hot electrons generated from the LSPR effect of visible-near-infrared light-excited H-W 18 O 49 NWs can be injected into MIL-125(Ti) NSs to increase the electron density and accelerate the reaction rate. Thus, the optimized H-W 18 O 49 NW/MIL-125(Ti) NS heterostructure exhibited good performance, achieving a CO yield of 202.37 μmol g -1 h −1 . This study enriches the diversity and architecture of available heterostructures for photocatalytic applications.
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2024
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IF 4.9
Nanqi Shi,Zhike Li,Xin Li,Hongxin Luo,Shuzhen Dong,Haiyan Li
Hexagonal boron nitride (h-BN), as a two-dimensional lamellar material, has been paid more and more attention in the field of corrosion protection because of its excellent thermal stability, chemical stability and insulation. In order to solve the problem that h-BN is difficult to disperse in resin, inspired by the adhesion ability of mussel secretions, the surface of h-BN was modified with polydopamine (PDA) to improve the dispersion of the fillers in epoxy resin, and the prepared corrosion inhibition CeO 2 nanoparticles were loaded on the surface. A functional filler CeO 2 &PDA/h-BN with corrosion inhibition effect was prepared. The surface morphology , chemical structure and thermal stability of functional fillers were analyzed by SEM, FTIR, XRD and thermogravimetric analysis . The test results show that after 40 days of testing, the low-frequency impedance modulus of the epoxy composite coating is 15 times that of the pure epoxy resin, and the wear resistance properties also significantly improved. The anti-corrosion mechanism of the composite coating is analyzed, and the synergistic effect of h-BN's barrier ability and CeO 2 's corrosion inhibition ability is revealed. This paper provides an idea for the preparation of multifunctional h-BN composite anticorrosive filler.
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ACS Applied Nano Materials
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2024
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IF 5.3
Yuting Li,Jiaming Song,Xin Zhao,Bingda Li,Zhuo Wang,Juanjuan Yang,Guoshuai Ban,Feng Teng,Jialong Ma,Chaoying Meng,Honggang Ye,Guangde Chen,Zhonghua Dai,Yu Cong
With increasing environmental pollution, the utilization of green techniques, such as photocatalysis, is required to degrade harmful sources without secondary pollution. In this study, we synthesized an efficient photocatalyst, i.e., a h-BN/BiPO4 heterostructure modified by Ag nanoparticles at the interface (Ag/BN/BPO) by photodeposition and a hydrothermal method, and investigated photocatalytic degradation performance for rhodamine B dye (RhB). It was found that 95% of RhB was removed by Ag/BN/BPO (optimal ratio) after 60 min of light exposure. Compared to BiPO4 and BN/BiPO4, the removal efficiency was improved by 50 and 30%, respectively. The high photocatalytic degradation activity of Ag/BN/BPO could be possibly attributed to the synergistic effect of the improved separation efficiency of electron–hole pairs by the special heterostructure design and the increased adsorption capacity due to the large specific surface area of the layered h-BN. This study provided a possible route for the development of highly efficient photocatalysts for the degradation of organic pollutants.
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ENVIRONMENTAL SCIENCE & TECHNOLOGY
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2024
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IF 10.8
Zhisong Liu,Haomiao Xu,Yurui Fan,Wenjun Huang,Feng Yu,Zan Qu,Naiqiang Yan
Ruthenium single-atom catalysts have great potential in ammonia-selective catalytic oxidation (NH3–SCO); however, the stable sp3 hybrid orbital of NH3 molecules makes N(sp3)–H dissociation a challenge for conventional symmetrical metallic oxide catalysts. Herein, we propose a heterogeneous interface reverse atom capture strategy to construct Ru with unique asymmetric Ru1N2O1 coordination. Ru1N2O1/CeO2 exhibits intrinsic low-temperature conversion (T100 at 160 °C) compared to symmetric coordinated Ru-based (280 °C), Ir-based (220 °C), and Pt-based (200 °C) catalysts, and the TOF is 65.4 times that of Ag-based catalysts. The experimental and theoretical studies show that there is a strong d–p orbital interaction between Ru and N atoms, which not only enhances the adsorption of ammonia at the Ru1N2O1 position but also optimizes the electronic configuration of Ru. Furthermore, the affinity of Ru1N2O1/CeO2 to water is significantly weaker than that of conventional catalysts (the binding energy of the Pd3Au1 catalyst is −1.19 eV, but it is −0.39 eV for our material), so it has excellent water resistance. Finally, the N(sp3)–H activation of NH3 requires the assistance of surface reactive oxygen species, but we found that asymmetric Ru1N2O1 can directly activate the N(sp3)–H bond without the involvement of surface reactive oxygen species. This study provides a novel principle for the rational design of the proximal coordination of active sites to achieve its optimal catalytic activity in single-atom catalysis.
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PubMed
高影响因子
JOURNAL OF CATALYSIS
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2012
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IF 6.002
Xiang Li,Yi Shi,Zhoujun Wang,Yahong Zhang,Yi Tang
In this paper, uniform H-β nanozeolite microsphere (β-ZMS) prepared by polymerization-induced colloid aggregation, combined with an immobilized lipase B from Candida antarctica (commercially available Novozym® 435), is applied as a racemization catalyst to the one-pot dynamic kinetic resolution (DKR) of aromatic sec -alcohols. The DKRs of various aromatic sec- alcohols can be carried out with high selectivity and conversion under optimum conditions. Importantly, it is found that, compared to commercial zeolites β (C-β), β-ZMSs display high selectivity for small sec- alcohol molecules because their shorter microporous channels reduce the diffusion time of substrate/product in the three-dimensional framework, and thereby decrease the possibility of secondary reactions. However, the β-ZMSs show a high racemization rate in the DKR of large sec- alcohol molecules, such as racemic 1-(1-naphthyl)-ethanol, thanks to their abundant accessible active sites. This observation will not only benefit the performance of acidic zeolite catalysts in one-pot DKR systems but also provide a new perspective on the application of nanozeolites in catalysis.
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Journal of the American Chemical Society
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2024
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IF 14.4
Yanliang Zhou,Lili Liang,Congying Wang,Fuxiang Sun,Lirong Zheng,Haifeng Qi,Bin Wang,Xiuyun Wang,Chak-tong Au,Junjie Wang,Lilong Jiang,Hideo Hosono
To date, NH3 synthesis under mild conditions is largely confined to precious Ru catalysts, while nonprecious metal (NPM) catalysts are confronted with the challenge of low catalytic activity due to the inverse relationship between the N2 dissociation barrier and NHx (x = 1–3) desorption energy. Herein, we demonstrate NPM (Co, Ni, and Re)-mediated Mo2CTx MXene (where Tx denotes the OH group) to achieve efficient NH3 synthesis under mild conditions. In particular, the NH3 synthesis rate over Re/Mo2CTx and Ni/Mo2CTx can reach 22.4 and 21.5 mmol g–1 h–1 at 400 °C and 1 MPa, respectively, higher than that of NPM-based catalysts and Cs–Ru/MgO ever reported. Experimental and theoretical studies reveal that Mo4+ over Mo2CTx has a strong ability for N2 activation; thus, the rate-determining step is shifted from conventional N2 dissociation to NH2* formation. NPM is mainly responsible for H2 activation, and the high reactivity of spillover hydrogen and electron transfer from NPM to the N-rich Mo2CTx surface can efficiently facilitate nitrogen hydrogenation and the subsequent desorption of NH3. With the synergistic effect of the dual active sites bridged by H-spillover, the NPM-mediated Mo2CTx catalysts circumvent the major obstacle, making NH3 synthesis under mild conditions efficient.
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FUEL
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2025
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IF 7.5
Shuping Li,Cheng Dong,Xuan Qi,Shiyong Chen,Lixiao Shen,Yinning Zeng,Yan Li,Zhenxin Yi,Lin Zhang,Shunguan Zhu
A novel hollow-structured thermite, n-Al/H-MoO 3 , is designed to enhance the energy release mode and combustion performance of solid propellant. This research comprehensively explores the preparation and structural features of n-Al/H-MoO 3 within solid propellants. Furthermore, a series of rigorous combustion tests, performance assessments, and computational simulations are conducted to investigate its practical application. Experimental results indicate that the significant improvements in combustion performance have been observed by integrating this innovation n-Al/H-MoO 3 in solid propellants as a burning rate modifier. The heat of explosion increases to 6135 J·g −1 , a 41.76 % increase over the blank group (M0). Furthermore, its flame temperature is 494.3°C higher than that of the blank group. These substantial gains are primarily attributed to the unique hollow structure of n-Al/H-MoO 3 , which facilitates the reaction between H-MoO 3 and Al in the gaseous phase region, thereby improving combustion dynamics. The research findings offer theoretical foundations and experimental support for the design of more efficient and stable propellants.
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CHINESE JOURNAL OF CATALYSIS
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2025
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IF 17.7
Lixia Li,Xiuqi Li,Feiyue Li,Xiang Zhen,Mingdong Dong,Jinxing Long,Xiaobing Wang,Zhiyong Jiang
Harnessing photocatalyzed hydrogen atom transfer (HAT) for the precise activation of C–H/O–H bonds is a pivotal yet challenging strategy to selectively drive oxidative C–C bond scission in renewable lignin, yielding value-added chemicals with exceptional selectivity. Herein, we present a metal-free photochemical strategy that enables selective C–C bond scission in lignin via a unique synergistic HAT pathway driven by triplet-excited 2-ethylanthraquinone (EAQ*) and hydroxyl radicals ( • OH) generated in situ from EAQH 2 and O 2 . Under simulated natural conditions, this process achieves a benzaldehyde yield of 146.6 mol% from a lignin-derived phenolic dimer. Mechanistic investigations reveal that preferential activation of the C α -OH in lignin facilitates a tandem HAT process, forming alkoxy radical intermediates that undergo β –scission to produce benzaldehyde, as corroborated by extensive control reactions and density functional theory calculations. Furthermore, this straightforward protocol efficiently cleaves the C–C bonds of technical kraft lignins, providing a rapid, scalable, and metal-free protocol for lignin valorization under mild conditions.
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CHINESE JOURNAL OF CATALYSIS
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2025
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IF 17.7
Qisong Yi,Lu Lin,Huawei Geng,Shaohua Chen,Yuanchao Shao,Ping He,Zhifeng Liu,Haimei Xu,Tiehong Chen,Yuanshuai Liu,Valentin Valtchev
The hydrothermal stability of zeolites is essential for their potential applications in biomass conversion, especially in processes involving elevated temperatures alongside the use or generation of H 2 O. In this study, we employed F - ions as mineralizers to synthesize hydrothermally stable ZSM-5 zeolites under acidic conditions. The acidic synthesis system promotes zeolites with fewer silanol-terminated lattice defects (ZSM-5(A)) compared to the traditional basic conditions (ZSM-5(B)), endowing materials with substantially higher structural integrity and hydrophobicity. After 10 days of autoclave treatment at 200 °C in aqueous phase, H-ZSM-5(A) demonstrated nearly unchanged reaction rates in the dehydration of cyclohexanol, while H-ZSM-5(B) lost > 50% of the dehydration activity. Additionally, H-ZSM-5(A) delivered higher initial dehydration rates compared to H-ZSM-5(B). The different measured activation energies further revealed variations in reaction pathways during cyclohexanol dehydration, i.e., the monomer- or dimer-mediated routes depending on the concentration of alcohol molecule within zeolite pores, providing additional evidence for the strengthened hydrophobic nature of H-ZSM-5(A). Beyond this, the zeolite surface properties and the strength of cyclohexanol-zeolite interactions may impose additional transport/adsorption barriers attributed to multi-phase phenomena on the more polar H-ZSM-5(B) zeolite surfaces. More importantly, the hydrothermal treatment did not induce significant desilication and dealumination in H-ZSM-5(A), thereby preserving its active acid sites and ensuring exceptional hydrothermal stability. The present work fundamentally studies the synthesis of hydrothermally stable zeolites in an acidic medium using fluorides and expands the understanding of polar interactions in catalysis, characterized by the dehydration of cyclohexanol, for future application in biomass conversion.
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