PETROLEUM SCIENCE AND TECHNOLOGY
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2017
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IF 0.655
Lanyu Xing,Zhenhao Wei,Zhenhao Wen,Xuedong Zhu
Hierarchical and conventional ZSM-5 zeolites were synthesized through steam-assisted crystallization approach using acid-treatment kaolin clay as the silica and aluminium sources. The samples were characterized by XRD, SEM, NH3-TPD, N2-physisorption and TG techniques. The results showed that hierarchical ZSM-5 had rich mesopores and bigger specific surface. In conversion of methanol to aromatics, hierarchical and conventional ZSM-5 zeolites showed higher selectivity for aromatics compared with commercial ZSM-5. Under the conditions of 450 °C, 0.15 MPa, the synthesized hierarchical ZSM-5 showed longest lifetime of 380 h, which was 2 and 6 times than those of conventional and commercial ZSM-5, respectively.
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Catalysts
·
2018
·Vol. 8
·期 2
·82
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IF 3.465
Yadong Bi,Xiaojuan Lei,Guihua Xu,Hui Chen,Jianli Hu
The hierarchical HZSM-5 and Hβ zeolites were prepared by alkaline post-treatment methods adopting Na2CO3, TMAOH/NaOH mixture, and NaOH as desilication sources, respectively. More mesopores are produced over two kinds of zeolites, while the micropores portion is well preserved. The mesopores formed in hierarchical Hβ zeolites were directly related to the basicity of the alkaline solution, indicating that Hβ zeolite is more sensitive to the alkaline post-treatment. The hierarchical HZSM-5 and Hβ zeolites are more active than the parent one for catalytic fast pyrolysis (CFP) of Kraft lignin. Hierarchical zeolites retained the function of acid catalysis, while additionally creating larger mesopores to ensure the entry of bulkier reactant molecules. The increase of the condensable volatiles yield can be attributed to the improvement of the mass transfer performance, which correlates well with the change of mesoporous surface area. In particular, the condensable volatiles yield for the optimized hierarchical Hβ reached approximately two times that of the parent Hβ zeolites. In contrast to the parent HZSM-5, the optimized hierarchical HZSM-5 zeolite significantly reduced the selectivity of oxygenates from 27.2% to 3.3%.Keywords:catalytic fast pyrolysis;Kraft lignin;hierarchical zeolites;HZSM-5;Hβ
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MATERIALS CHEMISTRY AND PHYSICS
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2017
·
IF 2.084
Yisong Wang,Tao Du,Ziyang Qiu,Yanli Song,Shuai Che,Xin Fang
Mesoporous ZSM-5 zeolite as the adsorbent supporting material was synthesized from rice husk ash (RHA), and then impregnated with polyethylenimine (PEI) for amine functional modification. A series of adsorbents (ZSM-5-PEI-X) with different PEI loading ratios were characterized by XRD , FTIR , TGA/DTG, nitrogen adsorption-desorption, SEM and EDX techniques. The measurement of the adsorption capacity at different temperatures was indicated that ZSM-5-PEI-30 had the highest adsorption capacity at 120 °C (1.96 mmol/g). The experimental data were fitted by adsorption kinetic models and isotherm models, indicated that fractional-order model and the Dual-site langmuir model can be used to describe the adsorption mechanism and predict the adsorption performance. The high CO 2 adsorption selectivity and regeneration stability suggested that this adsorbent is a potential candidate in the adsorption and separation of CO 2 in industrial flue gas .
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APPLIED CATALYSIS B-ENVIRONMENTAL
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2024
·
IF 20.2
Tianli Hui,Haowei Liu,Tonghui Li,Jinbo Pan,Tao Zheng,Rui Zhang,Xianghai Meng,Haiyan Liu,Zhichang Liu,Chunming Xu
The electrooxidation of 5-hydroxymethylfurfural (HMF) has emerged as a promising way to generate high-value-added products. However, evoking high-valence state NiOOH species as active sites to realize high current density remains a challenge. Herein, we report an efficient electrocatalyst for HMF electrooxidation based on phosphate anion intercalated layered double hydroxides (NiCo-Pi-LDHs). Onset potential at 1.16 V vs. RHE and current density of 200 mA/cm 2 at 1.41 V vs. RHE were realized. The intercalated phosphates act as proton transfer intermediates, facilitating the dehydrogenation of hydroxides to form oxyhydroxides while the protonated phosphate generated. The obtained oxyhydroxide oxidized HMF to 2,5-furandicarboxylic (FDCA) while cycling backward to hydroxide, accompanied by the cycle of protonated phosphate to phosphate. This novel strategy with dual-cycle of phosphate and nickel species can effectively evoke NiOOH species, thereby speeding up the reaction rate and having a great potential for biomass upgrading.
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FUEL
·
2024
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IF 6.7
Tingwei Zhang,Yongcan Jin,Huining Xiao
Sulfonated carbon/γ-Al 2 O 3 composites (AlSC-x, x = 1, 2, 3) were successfully prepared by the three-step method of impregnation-carbonization-sulfonation. The introduction of sulfonated sucrose-based carbon onto nano-γ-Al 2 O 3 enhanced its Brønsted acidity and weakened the original Lewis acidity. The Brønsted/Lewis acidity of the composite catalysts can be regulated by controlling the sulfonated carbon intake. AlSC-1 containing suitable Brønsted/Lewis acidity showed the best catalytic performance for converting glucose to 5-hydroxymethylfurfural (HMF). In monophasic DMSO/H 2 O (2.0/0.2 mL), an HMF yield of 62.3 % was achieved at 160 °C and 4.0 h when 0.02 g of glucose and 0.02 g of AlSC-1 were used. Adding a moderate amount of water into DMSO is crucial to improve HMF selectivity, and the DMSO/H 2 O system exhibited superior performance to other solvent systems, such as pure water, 1,4-dioxane/H 2 O, and GVL/H 2 O. More importantly, the recyclability of AlSC-1 was pretty good. In addition, AlSC-1 also exhibited much better performance than the other composite catalysts, including sulfonated carbon/nano-TiO 2 , sulfonated carbon/nano-ZrO 2 , and sulfonated carbon/nano-SnO 2 .
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ChemSusChem
·
2024
·
IF 7.5
Yanan Wei,Jianming Pan,Xu Yan,Yanli Mao,Yunlei Zhang
Graphical The AuPd/CeO 2 catalyst was employed for the oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA), showing that high oxygen vacancy of CeO 2 and electron-rich state of interfacial Au−Pd−CeO 2 can strengthen the adsorption and activation of HMF and molecular oxygen, greatly promoting the elimination of β -hydride for the conversion of HMF to FDCA. The design of high activity catalyst for the efficiently conversion of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) gains great interest. The rationally tailoring of electronic structure directly affects the interaction between catalysts and organic substrates, especially molecular oxygen as the oxidant. This work, the bimetallic catalysts AuPd/CeO 2 were prepared by the combining method of chemical reduction and photo-deposition, effectively concerting charge between Au and Pd and forming the electron-rich state of Au. The increasing of oxygen vacancy concentration of CeO 2 by acidic treatment can facilitate the adsorption of HMF for catalysts and enhance the yield of FDCA (99.0 %). Moreover, a series of experiment results combining with density functional theory calculation illustrated that the oxidation performance of catalyst in HMF conversion was strongly related to the electronic state of interfacial Au−Pd−CeO 2 . Furthermore, the electron-rich state sites strengthen the adsorption and activation of molecular oxygen, greatly promoting the elimination of β -hydride for the selective oxidation of 5-hydroxymethyl-2-furancarboxylic acid (HMFCA) to FDCA, accompanied with an outgoing FDCA formation rate of 13.21 mmol ⋅ g −1 ⋅ min −1 at 80 °C. The perception exhibited in this research could be benefit to understanding the effects of electronic state for interfacial sites and designing excellent catalysts for the oxidation of HMF.
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高影响因子
Molbank
·
2024
·Vol. 2024
·期 2
·M1818
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IF 0.6
Zhongwei Wang,Luxiao Zhou,Peng He,Yukun Qin
This study presents a novel approach in the realm of catalytic organic synthesis by integrating biomass catalytic conversion with organic synthesis techniques. UtilizingN-acetylglucosamine as the primary feedstock, the first phase of the research involves its catalytic transformation into 5-hydroxymethylfurfural (HMF). The subsequent phase employs a condensation reaction between HMF and 3,3-Dimethyl-2-butanone to synthesize a new compound, (E)-1-(5-(hydroxymethyl) furan-2-yl)-4,4-dimethylpent-1-en-3-one. This two-step process not only demonstrates the feasibility of converting biomass into valuable chemical precursors but also exemplifies the synthesis of novel compounds through green chemistry principles. The successful execution of this methodology offers fresh insights and opens new avenues for advancements in catalytic organic synthesis, emphasizing sustainability and efficiency.
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JOURNAL OF CATALYSIS
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2024
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IF 6.5
Qidong Hou,Yifan Nie,Xiaoran Zhang,Ruite Lai,Xinyu Bai,Chao Xie,Hengli Qian,Guanjie Yu,Tianliang Xia,Yao Tang,Chengxu Wang,Fei Qu,Haixin Guo,Meiting Ju
The conversion of biomass-derived carbohydrates to 5-ethoxymethylfurfural (EMF) is a fascinating reaction with 100% carbon atom utilization. Although effective conversion of 5-hydroxymethylfurfural (HMF) and fructose to EMF have been achieved, the direct conversion of glucose only gave low EMF yields. Herein, we reveal that the combinations of common Lewis acid with Brønsted acid in ethanol universally catalyze rapid etherification of glucose to intractable ethyl glucoside (EGL), as impedes the further conversion toward the desired products. The synergy of large-pore tin phosphate (SnPO) bearing strong Lewis acidic sites with acidic ionic liquid 1-(4-sulfobutyl)-3-methylimidazolium chloride (BSO 3 HMIMCl) enable tandem catalytic conversion of glucose, cellobiose and starch to EMF with record yields (61.7%, 61.8% and 55.7%, respectively), far exceeding previous reports. This transformation probably occurs via multiple parallel pathways, where water molecules generated by dehydration cooperate with acid and Cl - to hydrolyze EGL back to glucose, thus forming a positive feedback on EMF production.
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CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Yujie Ren,Shilin Fan,Bin Zhu,Peng Yang,Jinggang Wang,Soliman I. El-Hout,Jian Zhang,Chunlin Chen
The green synthesis of 2,5-furandicarboxylic acid (FDCA), famous as a bio-based polymer monomer from the 5-hydroxymethylfurfural (HMF), offers a promising route to reduce the usage of petroleum-based polymer polyethylene terephthalate. Although the electrocatalytic preparation of FDCA rids high temperature and pressure limits, most electrocatalysts used in the HMF oxidation reaction (HMFOR) are usually fabricated in harsh conditions. Therefore, we propose a method to improve the performance of electrocatalysts in the HMFOR reaction by introducing metal salts using natural seawater as the main feedstock. The final Co-sw/NF realized a 97.4% FDCA yield and 97.3% Faraday efficiency (FE). In-situ Raman techniques identified the catalytically active species of the catalysts employed in the HMFOR process. The effect of metal salts on catalyst energy levels is discussed in detail using the ultraviolet photoelectron spectroscopy (UPS) and Tauc plot method. The adsorption performance of HMF on the catalyst was determined by calculating the d-band centers and applying open circuit potential (OCP) tests. Furthermore, we elucidate the specific mechanism in terms of electron transport pathways.
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CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Changcheng Sun,Lyumeng Ye,Peng Lu,Xianhui Yan,Jianhang Huang,Zhixiong Tang,Dongyao Chen,Chaoping Cen
The key point to broaden the operating temperature window for synergistic control of NO x and oxygenated volatile organic compounds (OVOCs) with high NO x /VOCs conversion and N 2 /CO 2 selectivity relies on development of appropriate catalysts. Herein, a silver-modified Mn/HZSM-5 catalyst was designed, which achieved an effective NO x and acetone co-removal activity and maintained over 90 % N 2 /CO 2 selectivity at a broad temperature range from 293 to 400 °C. The excellent performance of MnAg/HZSM-5 was due to large surface area, plenty of oxygen vacancies and Lewis acid sites, as well as outstanding oxygen mobility and reducibility that derived from the interactions between Mn 4+ /Mn 3+ and Ag + /Ag 0 . NO x reduction followed both Eley-Rideal and Langmuir-Hinshelwood mechanisms, while acetone hardly replaced NH 3 as a reduction agent. Acetone oxidation underwent acetone → acetate → formate → carbonate → CO 2 and H 2 O following a Mars-van Krevelen mechanism. NH 3 participated in acetone oxidation, forming amide and nitrile species, which caused catalyst deactivation and secondary pollution.
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Nature Communications
·
2025
·Vol. 16
·期 1
·1-12
·
IF 15.7
Hu Yaqi,Liu Runze,Lu Kaiyun,Wu Daoning,Gao Pan,Hou Guangjin,Zhang Hongbo,Dai Weili
Hydrated hydronium ions formed in the pores/cages of zeolite catalysts are suggested as the active species that could impact the adsorption of reactant, the stability of intermediates or transition states, and the reaction mechanism in the aqueous phase alcohol dehydration. Nevertheless, under a typical vapor phase reaction condition, the relevant situation is still debatable. Herein, the promotion of water on cyclohexanol (CyOH) adsorption and dehydration under a vapor phase condition was clarified by in situ 1 H MAS NMR, 2D 1 H DQ MAS NMR and 2D 1 H- 27 Al HMQC NMR spectroscopy, systematic kinetic studies, isotope tracing and thermodynamic measurements. The water promoting effects were ascribed to water facilitating the formation of H 3 O + cluster (H 3 O + (H 2 O) n-1 ), and per Brønsted acid site (BAS) could be saturated by about 5 water at ambient temperature. The CyOH dehydration pathway was found to be highly dependent on the water concentrations, and a dimer reaction route with the C-H bond rupture as the kinetically relevant step (KRS) was verified as the main reaction pathway at high water concentrations. All these findings provide the deep insights into how water regulating the zeolite catalyzed dehydration reaction at a molecular level.
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CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Lei Zhang,Bingfeng Chen,Ti Zhou,Xiaomeng Cheng,Minghua Dong,Ye Liu,Huizhen Liu,Qingling Xu,Buxing Han
The conversion of carbohydrates into 5-hydroxymethylfurfural (HMF), a vital and valuable platform chemical, is sought after in industrial applications but poses significant challenges. In this research, we engineered an ultra-thin layer HTaMoO 6 catalyst using ball-milling/liquid-exfoliation technique, demonstrating its efficiency in catalyzing the transformation of carbohydrates to HMF. In contrast to the conventional method utilizing tetra(n-butylammonium) hydroxide as the intercalation agent, the ball-milling/liquid-exfoliation technique not only reduces catalyst preparation time (within 12 h) but also enhances the efficient intercalation, leading to the formation of an ultra-thin layer structure. The resulting catalyst exhibits high total acidity, a favorable Brønsted/Lewis acid ratio, and improved accessibility of active sites due to the thin layer structure post-exfoliation. Compared with bulk LiTaMoO 6 , the ultrathin layer HTaMoO 6 catalyst enables complete fructose dehydration with an HMF yield reaching 89.1 % under moderate reaction conditions (120 °C, 1 h) and 47.2 % yield of HMF is obtained from sucrose at 130 °C. This work provides a new method to fabricate the solid acid for the transformation of carbohydrates.
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