JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2024
·
IF 9.4
Yurui Xu,Xiao Liu,Minghui Jiang,Ning Li,Mingxue Su,Xin Du,Shiyu Li,Lei Lu,Suping Cui
Electrochemical carbon dioxide reduction reaction (ECO 2 RR) to produce high value-added products is a promising and effective strategy for closing the artificial carbon cycle and achieving sustainable development of resource. However, catalyst structural reorganization and agglomeration caused by the reduction process will reduce the catalytic performance. In this study, a carbon nitrogen shell with cupper-doped (CNCu shell) catalyst was prepared using silicon dioxide (SiO 2 ) as a template. The selectivity of the catalyst was controlled by precisely adjusting the form of Cu doping in the catalyst. When doped as single-atoms (CNCu 2.5 ), the catalyst exhibited a Faraday efficiency of up to 85 % for formate at −0.9 V versus reversible hydrogen electrode (vs. RHE). In contrast, when both Cu clusters and single-atoms coexisted (CNCu 25 ), the catalyst favored multi-carbon products, with a Faraday efficiency of 45 % for ethanol and 23 % for acetic acid. Density functional theory (DFT) calculations revealed the key mechanism for the difference in catalyst selectivity between the two doping forms. Cu single-atoms provided suitable binding energy to HCOO*, which increased the rate of CO 2 conversion to formate, while the combination of Cu clusters and single-atoms increased the adsorption of HCOO*, raising the rate-determining step energy of the formate pathway, which favored multi-carbon products. This study fundamentally revealed how different doping forms of metals affect catalyst selectivity, providing new insights and strategies for developing superior metal–carbon–nitrogen (M C N) catalysts.
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PubMed
高影响因子
CATALYSIS TODAY
·
2024
·
IF 5.2
Guiming Xie,Xingyang Bai,Fei Yu,Qingyuan Yang,Zhou-jun Wang
Three AuCu/ZnO bimetallic catalysts , AuCu/ZnO-BTC, AuCu/ZnO-BDC and AuCu/ZnO-MOF-74, were derived from various MOF precursors using facile hydrothermal methods . Among the resultant catalysts, the AuCu/ZnO-BTC catalyst possessed the best methanol synthesis activity, whose space time yield of methanol ( STY MeOH ) reached 359.0 g MeOH kg cat −1 h −1 at 250 °C under 3 MPa. Structural characterization reveals that in comparison with the AuCu/ZnO-BDC and AuCu/ZnO-MOF-74 catalysts, the AuCu/ZnO-BTC catalyst possessed higher specific surface area ( S BET ), tinier metal particle size, more oxygen vacancies , stronger metal-support interactions and larger amount of medium basic sites. In situ DRIFTS result demonstrates that formate (*HCOO) species were readily generated and bridged-methoxy (*b-OCH 3 ) species were selectively formed on the AuCu/ZnO-BTC catalyst, which may be related with its abundant oxygen vacancies and responsible for its superior methanol synthesis activity. The present work derives high-performance AuCu/ZnO bimetallic catalysts from MOF precursors and provides new insight into structure-activity relationships for CO 2 hydrogenation to methanol.
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Journal of Materials Chemistry A
·
2018
·Vol. 6
·期 7
·3151-3161
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IF 9.931
Yongqiang Gao,Zhihua Qiao,Song Zhao,Zhi Wang,Jixiao Wang
Mixed matrix membranes (MMMs) provide an efficient implementation that overcomes the bottleneck of individual inorganic or polymeric membranes for gas separation, but still face challenges. Here, we put forward a strategy of using in situ synthesized polymer grafted metal organic frameworks (MOFs) to eliminate both interfacial and carrier problems existing in the MMMs. Specifically, polyethyleneimine (PEI) grafted ZIF-8 (PEI-g-ZIF-8) was synthesized in situ by using Zn2+, 2-methylimidazole, and hyperbranched PEI through a rapid method at room-temperature. The chemical composition and porous structure of PEI-g-ZIF-8 were investigated by Fourier transform infrared spectroscopy, powder X-ray diffraction, N2 adsorption–desorption measurement, etc. The results indicated that the synthesized PEI-g-ZIF-8 achieves an enlarged pore volume and aminated surface. The improved interfacial compatibility between PEI-g-ZIF-8 nanoparticles and poly(vinylamine) (PVAm) was confirmed through high-sensitivity differential scanning calorimetry and zeta potential measurements. According to the CO2/gas separation tests, the MMMs incorporating with PEI-g-ZIF-8 achieved 1990 GPU of CO2 permeance and 79.9 of selectivity for CO2/N2 (15/85 vol%) separation, and 1790 GPU of CO2 permeance and 40.7 of selectivity for CO2/CH4 (10/90 vol%) separation, under 0.30 MPa gas pressure.
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Polymers
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2018
·Vol. 10
·期 3
·268
·
IF 2.935
Wenchao Sun,Baojiang Sun,Ying Li,Xiaonan Huang,Haiming Fan,Xinxin Zhao,Haoyang Sun,Wenxia Sun
Vinyl Benzoate/Heptadecafluorodecyl acrylate (VBe/HFDA) co-polymers were synthesized and characterized as thickening agents for supercritical carbon dioxide (SC-CO2). The solubility and thickening capability of the co-polymer samples in SC-CO2were evaluated by measuring cloud point pressure and relative viscosity. The molecular dynamics (MD) simulation for all atoms was employed to simulate the microscopic molecular behavior and the intermolecular interaction of co-polymer–CO2systems. We found that the introduction of VBe group decreased the polymer–CO2interaction and increased the polymer–polymer interaction, leading to a reduction in solubility of the co-polymers in SC-CO2. However, the co-polymer could generate more effective inter-chain interaction and generate more viscosity enhancement compared to the Poly(Heptadecafluorodecyl) (PHFDA) homopolymer due to the driving force provided by π-π stacking of the VBe groups. The optimum molar ratio value for VBe in co-polymers for the viscosity enhancement of SC-CO2was found to be 0.33 in this work. The P(HFDA0.67-co-VBe0.33) was able to enhance the viscosity of SC-CO2by 438 times at 5 wt. %. Less VBe content would result in a lack of intermolecular interaction, although excessive VBe content would generate more intramolecular π-π stacking and less intermolecular π-π stacking. Both conditions reduce the thickening capability of the P(HFDA-co-VBe) co-polymer. This work presented the relationship between structure and performance of the co-polymers in SC-CO2by combining experiment and molecular simulations.Keywords:supercritical CO2;shale gas;thickening agent;co-polymer;molecular simulation
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DESIGNED MONOMERS AND POLYMERS
·
2018
·
IF 1.37
Liang Xu,Tianyang Lei,Boyu Jing,Yu Zang,Fengjuan Miao,Toshiki Aoki,Masahiro Teraguchi,Takashi Kaneko
Three soluble hyperbranched polyazomethines containing oligosiloxane end group HBP-PAZ-SiOn were successfully synthesized. HBP-PAZ-SiOns were used as modifiers of ethyl cellulose (EC) and polysulfone (PS) membranes. Blend membranes, HBP-PAZ-SiOn/EC and HBP-PAZ-SiOn/PS were prepared by blending the THF solution of HBP-PAZ-SiOn with ethanol solution of EC and dichloromethane solution of PS, respectively. Surprisingly, the permeabilities for CO2 of the blend membranes were more than 15–16 times higher than those of pure EC and PS membranes without any drop of pemselectivity to N2. This unusual improvement has been achieved by both enhancement of diffusivity for carbon dioxide and nitrogen by the oligosiloxane groups and enhancement of affinity of the amino groups with carbon dioxide at the end groups of HBP-PAZ-SiOn.
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SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Xiaoyun Chen,Anteng Dai,Qinghai Long,Yutao Bai,Qifeng Zhang,Bihong Lv,Guohua Jing,Waseem Hayat,Zuoming Zhou
Solid-liquid phase change controllable absorbents can effectively regulate the solution absorption products as crystalline solids at the same time, but also to avoid the crystalline solid products in the early stage of the reaction throughout the continuous production, which can lead to equipment clogging, fouling and other problems. However, the structure-effect relationship of the regulator in the absorption solution is not clear at this stage. In this study, multistage amine/AMP/NMF solid–liquid phase change controllable adsorbents were fabricated to regulate the phase change nodes and product morphology of AMP/NMF-based solid–liquid phase change adsorbents using different structural multistage amines as regulators. Meanwhile, the effects of organic amines with different structural features as phase change regulators on solid–liquid phase change controllable absorbents were investigated by comparing the structural features (straight-chain amines, cycloalkyl amines, and symmetry of organic amines) and amine group types (primary and secondary amines). The results showed that ethylenediamine (EDA) and piperazine (PZ) could be used as solid–liquid phase change controllable absorbents for phase change modulation, however, the absorbents also underwent solid–liquid phase change near saturation and the products were in the form of crystal powder. Therefore, the influence mechanism of the regulators on the occurrence of phase change nodes and the formation state of the products is also described. The primary amino group tended to react with carbon dioxide (CO 2 ) to form carbamates and the secondary amino group tended to deprotonate. However, the protonated secondary amine group would weaken the interaction force between the products. During the reaction, mono-carbamates reduced the interaction strength of the process products and enhanced their solubility in the solvent making the reaction process homogeneous. The final product dicarbamate enhanced the interaction between the products and caused the products to self-aggregate and precipitate as crystalline solids. Straight chain amine EDA as a regulator, the final product was mainly through the strong hydrogen bonding effect, so that the product aggregation was crystalline; while the cycloalkyl amine PZ as a regulator, the final product could be not only through the strong hydrogen bond linked, but also formed a strong steric hindrance effect.
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Greenhouse Gases-Science and Technology
·
2025
·
IF 2.8
Qihang Wen,Yifei Feng,Haoyuan Gu,Haitao Yan,Zixu Yang,Minghui Zhu,Jing Xu
The performance of bimetallic catalysts is closely related to their surface structure, and the surface reconstruction process can affect the distribution of active sites, electronic structure, and reactant adsorption behavior. Traditional research has mostly focused on optimizing synthesis processes, such as controlling the size and distribution of metal particles, whereas there is relatively little research on the effect of pretreatment conditions on the dynamic structure of catalysts. In this study, a 10Ni─1Cu catalyst was synthesized using the deposition–precipitation method, and the effects of different pretreatment conditions on its performance were investigated. The catalyst was first pretreated at 500°C in a 60%H 2 /40%N 2 atmosphere, followed by reduction under different pretreatment atmospheres (10%H 2 /90%N 2 or 15%CO 2 /60%H 2 /25%N 2 ) at the same temperature. At 400°C and a space velocity of 30 L h −1 g −1 , the methane production rate of the catalyst treated in the reaction atmosphere significantly increased from 12.4 to 15.8 µmol g −1 s −1 compared to the catalyst treated with hydrogen alone. Characterization techniques, such as TEM, x-ray photoelectron spectroscopy (XPS), and diffuse reflectance infrared Fourier transform spectroscopy (CO-DRIFTS), were employed to study the structural properties of the catalysts, focusing on the surface properties after reduction and the surface species during the reaction. This study demonstrates that catalysts pretreated in the reaction atmosphere enhance methane production rates by regulating the surface structure and forming Ni─Cu alloy structures with a lower Ni/Cu ratio, thereby optimizing the selectivity of hydrogenation products.
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ACS Sustainable Chemistry & Engineering
·
2025
·
IF 7.3
Mei Ma,Jia-qi Bai,Huangfei Liu,Ben Liu,Zhangkai Qian,Suiqin Li,Jingshuai Chen,Mengdie Cai,Song Sun
The preparation of methyl-substituted amines by direct N-methylation of amines with CO2/H2 is an important reaction for CO2 utilization and organic synthesis. However, the design and construction of effective and stable non-noble-metal catalysts for this reaction remain challenging. Here, a cheap non-noble-Cu-based catalyst was prepared and applied in the direct N-methylation reaction of N-methylaniline with CO2 and H2. 5%Cu-ZnO(3.75%)/TiO2 showed 98.8% yield with an initial TOF of 7.7 h–1 after 24 h under 453 K, 1.5 MPa CO2, and 4.5 MPa H2, which was superior to 5%Cu/TiO2, 5%Cu/ZnO, and reported Cu-based catalysts. Furthermore, 5%Cu-ZnO(3.75%)/TiO2 can be reused at least four times and applied to the direct N-methylation of various amines with excellent selectivity. The various characterizations and experimental results showed that Cu0 was the active site, and 5%Cu-ZnO(3.75%)/TiO2 exhibited the largest surface Cu0 amount, thereby contributing to superior catalytic performance. The reaction mechanism of the direct N-methylation reaction of N-methylaniline with CO2 and H2 was proposed based on spectroscopic studies, kinetic studies, and control experiments. The reaction proceeded with the HCHO and N-methylformanilide intermediates, and the formation of HCHO from H2 and CO2 was the rate-determining step.
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ChemistrySelect
·
2024
·Vol. 9
·期 8
·e202304917
·
IF 1.9
M. S. Tao Song,M. S. Yimin Wang,Zhen Yuan,Hai Liu,B. S. Xiaoli Zhang,B. S. Li Cui,B. S. Yuewen Chen,Tianxia Liu,Xiya Zhang
Graphical The porous carbon material derived from Cu-doped ZIF-8 is first utilized for the electrocatalytic reduction of CO 2 to CO, exhibiting a CO Faradaic efficiency of 89 % and a satisfactory stability for over 13 hours. The high content of pyridinic nitrogen, large surface area, average pore size, and the presence of Cu-N 4 particles are proven to facilitate CO 2 adsorption and enhance the catalytic performance. Electrochemical reduction of carbon dioxide presents a promising pathway to tackle global energy and environmental challenges. Porous carbon materials from metal-organic frameworks exhibit high specific surface area, abundant active sites, and adjustable pore structure, demonstrating excellent electrocatalytic performance. With their abundant resources and tunability, copper-based catalysts are well-suited for efficient carbon dioxide conversion. However, the selectivity and stability of copper-based catalysts is poor. This study presents the preparation of the first Cu-doped ZIF-8-derived carbon materials and investigates their effect on electrocatalytic carbon dioxide reduction. At the optimal potential of −0.7 V vs . RHE, the CO Faradaic Efficiency (FE) of the Cu 0.5 -N−C catalyst reaches 89 %. Furthermore, the electrochemical current density and CO FE of Cu 0.5 -N−C catalyst remain nearly unchanged within 13 hours in 0.1 mol L −1 KHCO 3 electrolyte. Compared to most of the reported copper-based catalysts, Cu 0.5 -N−C exhibits better stability. Characterization results show that Cu 0.5 -N−C has a larger Cu-N 4 , higher pyridinic N content, larger specific surface area, and average pore size, which help promote CO 2 adsorption and enhance catalyst stability. This work provides new insights and pathways for electrocatalytic carbon dioxide reduction, with enormous potential to contribute to the global energy transition and environmental protection.
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SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Yidan Luo,Puxin Xu,Chao Liu,Huiyin Ye,Ke Peng,Shuohan Yu,Mingshan Xue,Yu Xie,Luhui Wang
Constructing heterostructures is an effective method for enhancing photocatalytic efficiency. Herein, a two-dimensional (2D)/2D heterojunction of NiAl-LDH/BiOBr with a built-in electric field (BIEF) was firstly synthesized. The photocatalytic efficiency of CO 2 reduction was assessed under visible light. And the findings revealed that the composite with 10 wt% NiAl-LDH demonstrated the highest CO 2 photoreduction performance, yielding a rate of 10.7 μmol·g −1 ·h −1 for CO generation, which was 21.4 and 4.3 times higher than that of pure NiAl-LDH and BiOBr. The heterojunction of the sample was type-II heterojunction with the analysis of XPS, band structures, and in-situ XPS. Photoluminescence (PL) and electrochemical tests demonstrated that the type-II heterojunction between NiAl-LDH and BiOBr efficiently enhanced the separation and transfer of electrons and holes, consequently boosting the photocatalytic performance. Besides, in-situ diffuse reflectance infrared Fourier transform spectroscopy (in-situ DRIFTS) was employed to reveal the reaction intermediates of CO 2 . This work provides experimental approaches and theoretical development of nanocomposite for photoreduction of CO 2 .
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
IF 8.1
Yangfan Xu,Tianze Han,Tingting Ji,Wenqian Luan,Ruiyang Zhao,Jishu Han,Lei Wang
Photocatalytic CO 2 reduction technology provides a promising approach to solve the energy and environmental problems. In this work, flower-like MnIn 2 S 4 microspheres were prepared by solvothermal method , and then calcined in air to obtain flower-like Mn doped In 2 O 3 (Mn:In 2 O 3 ) microspheres . Subsequently, Ni doped CdS (Cd 1-x Ni x S) nanocrystals were prepared and compounded with Mn doped In 2 O 3 to obtain Cd 1-x Ni x S/Mn:In 2 O 3 composite photocatalysts . It was found that Cd 0 · 96 Ni 0 · 04 S/Mn:In 2 O 3 had the best photocatalytic CO 2 reduction activity. The CO yield reached to 43.40 μmol g −1 in 3 h. The improved CO 2 reduction property were attributed to not only the increased light absorption capacity and the expanded surface area but also the enhanced charge separation efficiency that caused by the construction of Z-scheme heterostructure . The design and preparation of high-efficiency photocatalyst would be an effective way to promote the development of photocatalytic CO 2 reduction.
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APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Huarui Han,Songbai Zhang,Shushan Song,Weijie Zhang,Dandan Liu,Ziheng Song,Qianyu Wang,Changchang Ma,Sheng Feng,Xuemei Duan
In this study, a new type of 2D/2D Bi 2 O 3−x /NiAl-LDH (BO/NA-LDH) S-scheme photocatalyst was prepared by combining NiAl-LDH with Bi 2 O 3−x by wet chemical deposition for obtaining efficient photothermal-assisted photocatalytic reduction of CO 2 under simulated sunlight irradiation. In particular, the as-prepared optimal 50-BO/NA-LDH sample exhibited the CO production yield of 83.55 ± 2.76 μmol/g/h, which was 9 and 27 times that of BO (9.32 ± 0.62 μmol/g/h) and NA-LDH (3.09 ± 0.38 μmol/g/h), respectively. The enhancement of photothermal-assisted activity over the 50-BO/NA-LDH system was mainly attributed to the coupling of the photothermal conversion performance of Bi 2 O 3−x and improving the migration efficiency of interface carriers of S-scheme heterojunction and 2D/2D structure. This study presents a promising strategy for the development of high-efficient photothermal-assisted photocatalysts.
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