ACS Sustainable Chemistry & Engineering
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2020
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IF 7.632
Qingqing Guan,Jian Zhang,Liang He,Rongrong Miao,Yuzhen Shi,Ping Ning
As one of the organic carbon-rich feedstocks, Miscanthus sinensis is an interesting candidate for producing many high-value materials and chemicals. In this study, M. sinensis-derived activated carbon (msAC) particles with ca. 3.4 nm average pore size have been prepared by a simple carbonation method for supporting Pd nanoparticles (NPs) to hydrogenate acetylene. Catalytic test results showed that the 0.25% Pd/msAC catalyst could convert ∼99.9% of acetylene with ∼99.9% of ethylene selectivity. The life test result strongly demonstrated that the catalyst had a good durability for long-term (>100 h) acetylene hydrogenation with high conversion (∼99.9%) and ethylene selectivity (∼93.1%) at 260 °C with a space velocity of 80,000 h–1. The characterization results indicated that the msAC with the micro- and nanoscale pore structure and uniformly distributed oxygen-containing functional groups could efficiently disperse Pd nanoparticles and promote their Pd (111) crystal plane exposure. The above structure nature was co-contributing to the catalyst to choose the energetically favorable path for efficient acetylene hydrogenation and ethylene desorption. This work opens up valuable insights into the high-value utilization of M. sinensis biomass to design an efficient isolated Pd NP catalyst.
研究领域:
材料科学
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催化化学
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生物质利用
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2020
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IF 8.758
Tianxing Yang,Yuliang Feng,Rui Ma,Qiang Li,Hong Yan,Yanan Liu,Yufei He,Jeffrey T. Miller,Dianqing Li
In this work, a simple post-treatment has been carried out on a solid palladium–copper alloy to enhance the ethylene selectivity without any loss of activity. In all catalysts, PdCu/C catalysts post-treated at 375 °C exhibit improved ethylene selectivity (86%) compared to the solid PdCu/C catalysts (61%) at 100% acetylene conversion with comparable catalytic activity. During the post-treatment, the average size of PdCu nanoparticles is maintained at 6.6–6.8 nm, and no obvious segregation is observed. X-ray photoelectron spectroscopy and in situ extended X-ray absorption fine structure (EXAFS) results display that Pd is in a metallic state for all PdCu catalysts before and after post-treatment. Moreover, the EXAFS fitting results show that the Pd–Pd bond is gradually replaced by the Pd–Cu bond. The good separation of Pd atoms by Cu is also proven by XRD characterization, which shows that a body-centered cubic PdCu structure with uniform distribution of Pd and Cu in a unit cell forms under 375 °C post-treatment. The rearrangement of Pd and Cu atoms has a limited impact on the surface Pd dispersion, avoiding the activity loss due to the decrease in Pd sites. The improved selectivity could be attributed to the isolation of Pd and the accompanied d-band center downshifting, which favors the desorption of π-bonded ethylene species.
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
PubMed
高影响因子
RSC Advances
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2023
·Vol. 13
·期 35
·24628-24638
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IF 3.9
Ji-qiu Zhang,Yu-Hao Wang,Shu-jing Zhang,Yang-qian Lin,Qing-qing Guan,Xi-meng Xu
Acetylene hydrogenation is a well-accepted solution to reduce by-products in the ethylene production process, while one of the key technical difficulties lies in developing a catalyst that can provide highly dispersed active sites. In this work, a highly crystalline layered covalent organic framework (COF) material (TbBpy) with excellent thermal stability was synthesized and firstly applied as support for ultrasmall Pd nanoparticles to catalyze acetylene hydrogenation. 100% of C2H2 conversion and 88.2% of C2H4 selectivity can be obtained at 120 °C with the space velocity of 70 000 h−1. The reaction mechanism was elucidated by applying a series of characterization techniques and theoretical calculation. The results indicate that the coordination between Pd and N atom in the bipyridine functional groups of COFs successfully increased the dispersibility and stability of Pd particles, and the introduction of COFs not only improved the adsorption of acetylene and H2 onto catalyst surface, but enhanced the electron transfer process, which can be responsible for the high selectivity and activity of catalyst. This work, for the first time, reported the excellent performance of Pd@TbBpy as a catalyst for acetylene hydrogenation and will facilitate the development and application of COFs materials in the area of petrochemicals.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INORGANIC CHEMISTRY
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2025
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IF 4.7
Changjin Xu,Yinglei Liu,Huiqing Guo,Chun Du,Gaowu Qin,Song Li
The ability to finely tune the nuclearity of active metal sites is critical for designing highly selective catalysts, especially for hydrogenation processes. In this work, we developed a novel PdCu catalyst with an ordered body-centered cubic (BCC) structure, enabling precise control over Pd nuclearity to optimize selectivity. Using a facile polyol synthesis method, we modulated the Pd coordination environment, reducing the Pd–Pd coordination number from 3 (disordered face-centered cubic, FCC) to 0 (ordered BCC), thereby achieving full isolation of Pd by the surrounding Cu atoms. This structural transformation enhances hydrogen spillover and weakens ethylene adsorption, resulting in superior activity for the selective hydrogenation of acetylene to ethylene. The ordered PdCu supported on Al2O3 (o-PdCu/Al2O3) achieved a 99% acetylene conversion with an 84.5% ethylene selectivity at near-room temperature. This work highlights the importance of controlling atomic-scale nuclearity in metal catalysts and provides a promising strategy for improving the catalytic efficiency and selectivity in industrially significant processes.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS A-GENERAL
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2018
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IF 4.521
Yiqi Xu,Yishu Jiang,Hao Xu,Qingtao Wang,Weimin Huang,Haihua He,Yuanyuan Zhai,Shuxia Di,Lingling Guo,Xiaoliang Xu,Jia Zhao,Feng Feng,Qunfeng Zhang,Xiaonian Li
Designing the electron-rich palladium active site is of great importance to enhance the selectivity of ethylene in acetylene semi-hydrogenation. In this work, ionic liquids, the effective electronic modifier, were mingled with palladium solution to be immobilized on Al 2 O 3 by incipient impregnation method. X-ray photoelectron spectra characterization was conducted to characterize the structure of catalysts, suggesting that some ionic liquids can form unique carbene structure. The catalytic results showed that those immobilized ionic liquids that can form unique carbene structure exhibited much higher selectivity of ethylene than those cannot. The above results were obtained because carbene can donor the electron to palladium, enriching the electron density of palladium and therefore facilitating the desorption of ethylene. The findings of the unique carbene structure derived from ionic liquids in this work provide an efficient strategy to design the catalyst to improve the selectivity of the intermediate in other partial hydrogenationreactions.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY
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2021
·
IF 2.63
Dong Chen,Rongrong Miao,Liang He,Qingqing Guan
Ethyne is often an unwanted impurity in ethene streams used in plastics industry. Supported Pd catalysts offer high ethyne conversion, but poor ethene selectivity due to over-hydrogenation which leads to the formation of carbonaceous deposits. In this paper, acrylamide was grafted by free radical polymerization onto bagasse pith hemicellulose (to form HEMI-g-AAMs), which was then used as a porous bio-based carrier of Pd nanoparticles. The obtained Pd/HEMI-g-AAMs catalyst showed an ethyne conversion and ethene selectivity of 100% and 94.70%, respectively, at 100 °C and a space velocity of 70,000 h−1. The nitrogen-rich bio-based support regulated the physicochemical properties and catalytic activity of the supported Pd nanoparticles. Results guide the development of new and improved Pd-based catalysts for the partial catalytic hydrogenation of ethyne to ethene.
研究领域:
化学工程
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催化材料科学
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产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2019
·
IF 0
Haijun Chen,Zhimin Li,Zhaoxian Qin,Hyung J. Kim,Hadi Abroshan,Gao Li
Selective conversion of acetylene impurities to ethylene is a major step in processing chemical feedstock in industry. Currently, this step is widely performed through the catalytic hydrogenation of acetylene over palladium-based materials. Because of a lack of selectivity, however, this method suffers from the formation of ethane to a considerable extent. Herein, we present gold nanoclusters encapsulated in microporous silica as robust catalysts for the hydrogenation of acetylene with 98% selectivity toward ethylene formation. These encapsulated catalysts are designed to avoid the aggregation of nanoclusters during thermal pretreatment at ∼500 °C by maintaining an average nanocluster size of around 1.6 nm. This approach yields an acetylene conversion efficiency of ∼95% at 280 °C. The catalysts are characterized by UV–vis, Fourier transform infrared, NMR, and X-ray spectroscopies as well as density functional theory. Analysis shows that preservation of the nanoscale size of the gold particles at operating temperature coupled with the maintenance of positive charges on the surface active sites induced by the presence of electronegative species of microporous silica can be utilized as an efficient strategy to significantly improve acetylene activation for the semihydrogenation reaction.
研究领域:
化学工程
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催化科学
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材料科学
✓ 已验证
产品关联
DOI
Surfaces and Interfaces
·
2024
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IF 5.7
ZiHao Tao,Liuyi Pan,Hedan Yao,Long Chao,Louwei Cui,Chongpeng Du,Yingxia Wang,Yinshang Xi,Dong Li,Wenhong Li
The semi-hydrogenation of acetylene represents a crucial industrial process, with the catalytic conversion of trace acetylene in ethylene-rich streams, achieved without pretreatment, offering a greener and more sustainable approach. A bimetallic NiCo@C catalyst was synthesized through the pyrolysis of a metal-organic framework (MOF) precursor. During pyrolysis, the organic ligands form a uniform carbon layer, effectively protecting the metallic active sites formed. This process yields alloy nanoparticle catalysts characterized by a high surface area and a complete carbon layer. The formation of the NiCo alloy facilitates a geometric isolation of Ni by Co, coupled with electronic modification, which ensures high selectivity for conversion. In addition, the outer carbon layer preserves elements of the original MOF spatial structure, exhibiting a high specific surface area and dispersion, thus enabling the rapid desorption of ethylene post-reaction. Density functional theory (DFT) calculations were employed to explain the semi-hydrogenation mechanism of acetylene on the carbon-layered NiCo alloy. In a flow reactor designed for acetylene hydrogenation, the combination of bimetallic interaction and carbon layer protection produced a catalyst conversion rate of 95 % and a selectivity of 83 %. In conclusion, the NiCo alloy, effectively shielded by the carbon layer derived from the organic ligands during pyrolysis, exhibits enhanced catalytic performance due to the interaction of the bimetallic components.
研究领域:
催化化学
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材料科学
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能源化工
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
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2022
·
IF 8.047
Leisheng Che,Jinqiu Guo,Zhiwei He,Hongbo Zhang
We report here that the reduction degree of the metal at the catalytic interface dominates the reactivity of acetylene hydrogenation, mainly in terms of turnover rates (TORs) and activation energies, which could certainly cause the switch of kinetically relevant steps (KRS) from “C 2 H 3 *+H*” over Ce(OH)SO 4 ·xH 2 O dispersed Pd catalyst to “C 2 H 4 *+H*” elementary step over Pd/CeO 2 . Besides, a compact kinetic model has been established to describe the reaction process and the dissociative mechanism was confirmed by H 2 /D 2 exchange experiment. Meanwhile, the rate-determining step (RDS) and the main adsorbed species of the reaction were confirmed by systematic kinetic studies as well as in-situ FTIR analysis. More importantly, with the aid of parity fitting and gas isothermic adsorption analysis, the energetic relationship among the steps along with the acetylene hydrogenation is quantitatively described, which provides a good support and complement for the previous research, and helps researchers build up advanced reaction systems.
研究领域:
化学动力学
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催化
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表面化学
✓ 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）