FUEL
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2022
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IF 8.035
Yueqing Wang,Hongxing Wang,Junbo Zhang,Hongyan Zheng,Long Huang,Yulei Zhu
Selectively converting fructose into furfural by H-beta catalyst is a very interesting catalytic process. However, it is a challenging task to clearly elucidate the roles of framework Al for selective scission of C C and C O bond. Herein, selective elimination of framework Al atoms is realized. Several detailed investigations showed that the framework Al species located in different sites play important role in furfural formation. The framework Al atoms of pristine H-beta mainly occupied at T1, T2, T5, T6 and T7 sites. These Al species at pore mouth can be removed by citric acid, while the treatment of nitric acid mainly eliminated the framework Al atoms from T2 and T7 sites. As for oxalic acid, the Al atoms occupied at T2, T5, T6 and T7 was primarily leached. Upon citric acid and nitric acid treatment afforded the similar yield of furfural, indicating that the formation of furfural could not be governed by these Al species at pore mouth, T2 and T7 sites. However, in the case of oxalic acid treatment, complete removal of the Al species on T2, T5, T6 and T7 sites decreased the yield of furfural. Thus, it is reasonably inferred that these Al atoms populated at T1 sites and intersecting channels is more encouraging for the splitting of C C bond, while the Al species occupied at T5, T6 sites and the larger straight channels is probably more favorable to scission of C O bond.
研究领域:
催化化学
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材料科学
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产品关联
DOI
高影响因子
Journal of Materials Chemistry A
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2024
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IF 10.7
Yuhui Huang,Yehan Tao,Qingqing Wang,Jian Du,Jinwen Hu,Jie Lu,Yanna Lv,Haisong Wang
To develop an industrial zeolite-based catalyst for efficient furfural production, the acidity, pore structure, and electronic properties of H-β zeolite were modulated by synergistic deatomization and atomic implantation treatments. The dealumination effectively decreased the intrinsic aluminum-related Lewis and Brosted acid sites, thus decreasing the occurrence of unwanted side reactions. Meanwhile, the removed skeleton aluminum can create voids for the following atomic implantation of introducing higher valent-state niobium species, which would provide new kinds of catalytic active sites, increase the average pore size by distorting the zeolite skeleton, and enhance the interaction with reactant molecules by acting as more electron deficient centers. In a single-phase water/γ-valerolactone reaction system, the optimum catalyst can efficiently convert both xylan and xylose with a conversion of 100 % at a medium temperature of 130 ℃ within 3 hours. Compared with the furfural yield over untreated H-β (12.7%), the yield over deAlβ/Nb(20%) catalyst was greatly enhanced by 54% with xylose as raw material. The catalyst can be recovered by simple cleaning and thermal regeneration and then reused. The proposed post-treatment strategy could maintain the integrity of the zeolite structure, ensure uniform and stable metal dispersion under harsh conditions, manage the complexity and cost of the preparation process, and most importantly, optimize the catalytic performance. Addressing these issues is essential for improving the efficiency and practical application of industrial zeolite catalysts by this general approach and benefiting industrial furfural production.
研究领域:
化学工程
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催化材料
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DOI
高影响因子
RSC Advances
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2015
·Vol. 5
·期 125
·103695-103702
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IF 3.84
Yuannan Xiong,Wenqi Chen,Jianjun Ma,Zhihua Chen,Aiwu Zeng
The continuous liquid-phase Friedel–Crafts acylation of furan with acetic anhydride was first carried out in a fixed-bed reactor over an H-beta zeolite. A three-level, four-variable Box-Behnken design combined with response surface methodology was employed to determine the optimal acylation conditions, and the accuracy of the model was verified by validation experiments. In this study, it was found that lower liquid velocity and stronger polarity of the solvent were conducive to enhancing the catalytic activity and stability of the H-beta zeolite. The reaction was limited by the acid sites being poisoned due to the adsorption of the by-product and pore blockage. Moreover, the carbon deposit was proved to be the main reason for the deactivation of the H-beta zeolite by using GC-MS, 13C NMR MAS, 27Al NMR MAS, TG/DTG and NH3-TPD.
研究领域:
催化化学
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材料科学
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产品关联
DOI
高影响因子
CATALYSIS TODAY
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2022
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IF 6.562
Xinyi Xing,Ying Guan,Liping Zhang,Xian Shi,Han Wu,Hui Gao,Siquan Xu
A catalytic system that is both efficient and recyclable is desirable for production 5-hydroxymethylfurfural (HMF) from glucose. In this study, the catalytic system composed of H 2 O (NaCl) -tetrahydrofuran (THF) biphasic system and H-β zeolite was found to have excellent performance for the glucose conversion into HMF. The physicochemical properties of the H-β zeolite catalyst, the dosage of the system components, and the reaction parameters were investigated in detail to optimize the production efficiency of HMF. Under optimal reaction conditions, an advanced level of 84% HMF yield was obtained from glucose. After the reaction was completed, all components of the catalytic system can be recovered, realizing no waste of reagents. Moreover, the recycled H-β(30) zeolite catalyst maintained considerable catalytic stability after five consecutive cycles. Therefore, it is reasonable to believe that the efficient, inexpensive, and recyclable H 2 O (NaCl) -THF catalytic system containing H-β(30) zeolite is capable of showing promising application potential in the future.
研究领域:
催化化学
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可再生资源转化
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产品关联
DOI
高影响因子
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.
研究领域:
化学工程
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环境科学
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催化材料
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）