APPLIED CATALYSIS A-GENERAL
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2020
·
IF 5.006
Peng Zhang,Ziyan Wang,Yan Zhang,Jian Wang,Wenqing Li,Lina Li,Peiping Zhang,Cundi Wei,Shiding Miao
In this work a Pd/Fe-Co-Ni layered double hydroxide (LDH) composite was prepared and investigated in the semi-hydrogenation of 2-methyl-3-butyn-2-ol (MBY). Hollow nanocages of ternary Fe-Co-Ni LDH were constructed by stacking the LDH nanosheets edge-to-face which inherited the rhombic dodecahedral structure of ZIF-67 templates. Uniform palladium (Pd) nanocrystals with cubic shapes were imbedded in the LDH nanocages via a solvothermal method. The hydroxyl groups on LDH supports were critical to inhibit the association of excess hydrogen atoms on the catalyst, so less MBY molecules were converted to 2-methyl-2-butanol (MBA) during the hydrogenation catalysis. Under optimized reaction conditions the hydrogenation activity of Pd/Fe-Co-Ni LDH was significantly improved, and the conversion of MBY was higher than 99% with selectivity of 2-methyl-3-buten-2-ol (MBE) exceeding 99%. The catalyst was easily recovered and had little reduction in catalytic performance during the cycling reactions.
研究领域:
化学工程
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催化科学
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产品关联
DOI
高影响因子
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
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2016
·Vol. 95
·期 6
·1109-1116
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IF 1.066
Jianqiang Zhang,Jian Luo,Jun Gao,Dianhua Liu
Catalytic hydrogenation of acetic acid to ethanol was investigated in a fixed-bed micro-reactor with calcium silicate-modified platinum-tin catalyst at mild reaction condition. The modified catalyst exhibited excellent performance for the ethanol synthesis process at relatively low pressure. According to the results of H 2 -pulse chemisorption experiments, the introduction of calcium silicate promoted the dispersion of platinum particles. The NH 3 -TPD and H 2 -TPR results showed the decrease of acid content on catalyst surface and the enhancement of reducibility after the CaSiO 3 modification. Additionally, the results of XPS indicated that Sn (0) was emergent and Pt (2+) was sharply decreased after reduction. Both the H 2 -TPR and XPS results supported the formation of Pt-Sn alloy during the reduction process at 623 K. The Pt-Sn alloy changed the electron density and benefited the free hydrogen dissociation and hydrogenation. The enhancement of reaction temperature and pressure both promoted acetic acid conversion. The kinetic model of power-function type was established to describe the process of hydrogenation. The results of residual analysis confirmed that the raised kinetic model for acetic acid to ethanol reaction was suitable.
研究领域:
化学工程
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催化科学
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产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
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2022
·Vol. 46
·期 35
·16941-16950
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IF 3.925
Shuai Wang,Feng Li,Yanxiu Liu,Qiang Zhang,Hua Song
A series of stable N-doped porous carbon encapsulated Ni nanoparticles (Ni@CN) were prepared via direct pyrolysis of Ni-MOF-74(N) and utilized for the catalytic transfer hydrogenation (CTH) of phenol to cyclohexanol with isopropanol as a hydrogen donor. The prepared catalysts were characterized by means of TG, XRD, BET, SEM, TEM and XPS. The effects of preparation and reaction conditions on the CTH performance were investigated. The results showed that the Ni particles of Ni@CN were smaller than that of Ni@C, which reflected that the doping of nitrogen could improve the dispersion of Ni nanoparticles. Moreover, electrons can be redistributed with N-doping. These two factors contribute to better catalytic activity. The Ni@CN-450 catalyst exhibited 99.3% phenol conversion with 100% cyclohexanol selectivity. Moreover, the catalysts could be recycled and reused easily with the help of a magnet and its catalytic performance did not decrease obviously even after five successive cycles.
研究领域:
化学工程
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材料科学
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DOI
高影响因子
RSC Advances
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2016
·Vol. 6
·期 56
·51221-51228
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IF 3.289
Yanliang Yang,Jiping Ma,Xiuquan Jia,Zhongtian Du,Ying Duan,Jie Xu
Al2O3 modified by alkaline earth metals M–Al2O3 (M = Mg, Ca, Sr, Ba) was synthesised by coprecipitation method. The nickel-based catalysts supported by M–Al2O3 were prepared by impregnation method. The catalysts were characterized by TEM, N2 adsorption/desorption, XRD, H2-TPR, NH3-TPD and XPS, and used for the direct hydrogenation of furfural to tetrahydrofurfuryl alcohol (THFA) in water. The reaction was demonstrated to proceed through furfuryl alcohol as an intermediate. The modification of Al2O3 by alkaline earth metals has a significant effect on the activity and selectivity of THFA. A high yield of THFA was obtained over Ni/Ba–Al2O3 under optimized conditions. Moreover, the catalyst is recyclable and reusable at least four times without significant loss of the conversion of furfural and selectivity of THFA.
研究领域:
催化化学
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绿色化学
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产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Qiumei Hou,Jingxuan Cai,Li Zuo,Hui Chen,Yuchuan Fu,Jianyi Shen
Supported Ni (60 wt% Ni) catalysts were prepared and phosphided into corresponding Ni 2 P catalysts. They were used for the hydrogenation of furfural as well as for the probe reactions (the hydrogenation of furan and propanal). The results demonstrated that the acidic support promoted the adsorption and hydrogenation of furan ring and aldehyde group over the nickel sites while the basic support played the opposite role. The IR spectra demonstrated that the aldehyde group was more easily hydrogenated than the furan ring at room temperature, implying the sequential hydrogenation of furfural to furfuryl alcohol (FA) and then to tetrahydrofurfuryl alcohol (THFA) over Ni. The microcalorimetric studies revealed that both the aldehyde group and furan ring were strongly adsorbed on Ni so that the Ni catalysts were highly active to hydrogenate the two groups, i.e., the Ni catalysts favored the formation of THFA. On the other side, although the adsorption heats of aldehyde group were much lower on Ni 2 P than on Ni, the adsorption heats were significantly higher for aldehyde group than for furan ring on Ni 2 P, implying the high selectivity to FA on Ni 2 P.
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 CATALYSIS
·
2023
·
IF 7.3
Mengya Guo,Feng Wang,Mingwei Zhang,Li Wang,Xiangwen Zhang,Guozhu Li
Encapsulation of clean metal nanoparticles (NPs) into interior of metal–organic framework (MOF) is of great importance to remarkably improve the stability and tune the catalytic performance of metal NPs. Herein, highly dispersed Pt NPs are encapsulated in UiO-66 with different functional groups on linker (UiO-66-X, X = F, H, NH 2 , OH) through enhanced electron attraction of metal precursor by MOF node and proper reduction by H 2 /Ar gas. Compared with traditional impregnation method, the encapsulation method gives well-defined Pt NPs and controllable microenvironment. Detailed characterizations reveal that functional group of the linker can effectively tune the microenvironment and electronic properties of guest Pt NPs. In situ FTIR was utilized to investigate the adsorption capability and strength of reactants on the catalysts. The electron-deficient Pt species and appropriate surface hydrophobicity match well with the reactants, which is responsible for enhanced catalytic hydrogenation activity of C C and nitro groups. The surface hydrophobicity plays a major role in promoting alkyne hydrogenation. This work is devoted to rationalize the relationship between hydrogenation performance and catalyst property of UiO-66 encapsulated Pt NPs, in terms of energy adaptability in electronic state and structure adaptability in surface chemistry. Rational design strategy of Pt-confined-in-MOF composites through molecular level regulation is provided for hydrogenation.
研究领域:
材料科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
TRANSACTIONS OF TIANJIN UNIVERSITY
·
2024
·
IF 6.7
Meng Zhaohui,Liao Ying,Liu Ling,Li Yaqian,Yan Hao,Feng Xiang,Chen Xiaobo,Liu Yibin,Yang Chaohe
Improving the efficiency of metal/reducible metal oxide interfacial sites for hydrogenation reactions of unsaturated groups (e.g., C=C and C=O) is a promising yet challenging endeavor. In our study, we developed a Pd/CeO 2 catalyst by enhancing the oxygen vacancy (O V ) concentration in CeO 2 through high-temperature treatment. This process led to the formation of an interface structure ideal for supporting the hydrogenation of methyl oleate to methyl stearate. Specifically, metal Pd 0 atoms bonded to the O V in defective CeO 2 formed Pd 0 –O V –Ce 3+ interfacial sites, enabling strong electron transfer from CeO 2 to Pd. The interfacial sites exhibit a synergistic adsorption effect on the reaction substrate. Pd 0 sites promote the adsorption and activation of C=C bonds, while O V preferably adsorbs C=O bonds, mitigating competition with C=C bonds for Pd 0 adsorption sites. This synergy ensures rapid C=C bond activation and accelerates the attack of active H* species on the semi-hydrogenated intermediate. As a result, our Pd/CeO 2 -500 catalyst, enriched with Pd 0 –O V –Ce 3+ interfacial sites, demonstrated excellent hydrogenation activity at just 30 °C. The catalyst achieved a Cis–C18:1 conversion rate of 99.8% and a methyl stearate formation rate of 5.7 mol/(h·g metal ). This work revealed the interfacial sites for enhanced hydrogenation reactions and provided ideas for designing highly active hydrogenation catalysts.
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
ACS Sustainable Chemistry & Engineering
·
2020
·
IF 7.632
Lei Ye,Yiwen Han,Hui Bai,Xuebin Lu
Bifunctional heterogeneous catalysts (HZ-ZrP) were prepared by using HZSM-5 as the carrier to support a zirconium phosphate (ZrP) active component for the one-pot value-added conversion of biomass-derived furfural (FAL). By changing the loading amount of ZrP, the ratio of Lewis to Brønsted acid (2.7–15.4) and the acid strength of the catalysts can be adjusted. HZ-ZrP-5 and HZ-ZrP-16 were selected for the production of different value-added chemicals, and a total yield of up to 93.8% (i-PL and GVL) and 64.2% (GVL) were obtained using isopropanol as the hydrogen donor under optimized conditions, respectively. Furthermore, stability and recyclability of the catalyst were also tested and showed no significant drop in total yield after recalcination. The catalysts have high activity (Ea = 27.05 ± 3.08 kJ mol–1), but the ring-opening reaction restricted the cascade reaction. In addition, a possible reaction pathway and mechanism for the FAL conversion were proposed.
研究领域:
催化化学
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生物质能
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2019
·
IF 7.723
Lei Yang,Shiyi Yu,Chong Peng,Xiangchen Fang,Zhenmin Cheng,Zhiming Zhou
A series of nonprecious monometallic Ni/AlSBA-15 and bimetallic Ni M (M = Zn, Ga, Cu, or Fe)/AlSBA-15 catalysts were prepared using a urea precipitation method and applied to the semihydrogenation of phenylacetylene. The catalysts were characterized by various techniques, showing that the Ni particle size of catalyst can be tuned by adjusting the Al content, and NiZn and NiGa supported catalysts exhibited geometric and electronic effects that originated from the bimetallic alloy. Among all the catalysts studied, NiZn 3 /AlSBA-15, with a turnover frequency of 10.89 s −1 comparable to that of precious Pd-based catalysts, presented the highest selectivity to styrene (90.3%) at nearly 100% conversion of phenylacetylene in semibatch operation. This catalyst was further evaluated in a continuous fixed-bed reactor for semihydrogenation of a model C 8 aromatic fraction of pyrolysis gasoline (a mixture of phenylacetylene, styrene, ethylbenzene and xylene), which aimed at assessing its practical application of recovering styrene from pyrolysis gasoline. The results showed that at complete conversion of phenylacetylene, the styrene concentration in the product was always kept at a stable level and higher than its initial concentration over 100 h of time on stream, demonstrating high selectivity and good stability of NiZn 3 /AlSBA-15. Finally, the application of NiZn 3 /AlSBA-15 was extended to other phenylacetylene derivatives.
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
MICROPOROUS AND MESOPOROUS MATERIALS
·
2024
·
IF 4.8
Hongyan Wang,Xinyue Sun,Jingpei Cao,Yajie Tian,Bofeng Zhang
Zeolite catalysts have been widely applied in petroleum and chemical industries. Nano/hierarchical structure could improve the utilization efficiency of active sites, especially for metal species encapsulated in zeolites. However, the uniformity of zeolite surface and crystallinity would decrease, leading to low stabilization effect. Herein, we developed a seed-directed method to prepare Pd clusters (∼1.3 nm) regioselectively encapsulated in hollow polycrystalline shell of Silicalite-1 zeolite. In nitrobenzene hydrogenation reaction, the optimized Pd@S-1-hp showed a high conversion of 92.2 % at 110 °C, which is 40 % higher than that of Pd clusters in bulk zeolite. Sub-nano Pd species in polycrystalline shell could significantly shorten the diffusion length on the basis of strong microporous confinement effect. Catalytic hydrogenation activity remained stable after six cycles. This structure could be extended to heterogeneous reactions suffering from diffusion limitation.
研究领域:
化学工程
·
催化材料
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Jianguo Liu,Nan Wang,Jianan Liu,Ming Li,Ying Xu,Chenguang Wang,Yanzhi Wang,Haoquan Zheng,Longlong Ma
Highly selective catalytic hydrogenation of alkynes to alkenes is a highly important reaction owing to its industrial and commercial application. Specifically, semihydrogenation of terminal alkynes has been more challenging than internal alkenes even using Lindlar catalysts. Also, the high reduction degree state metal-supported catalysts like Pd0/C, Pt0/C, and Ru0/C have been well-known to be used widely in hydrogenation due to their super activity. However, charcoal can absorb a large amount of water; Pd/C with 50% water is convenient on a large-scale synthesis. Charcoal generally bears oxygen groups on its surface, which are responsible for low selectivity and undesired products. Even typically, only 10–60% of the Pd metal atoms are exposed, they still suffer from poor stability in acids owing to leaching. Herein, we intend to design active and stable metal catalysts with features as the following to avoid leaching: having strong interaction with the support and coordinatively unsaturated metal sites or low valence state metals physically isolated from the acid environment. Herein, a highly efficient semihydrogenation of terminal alkynes to produce alkenes has been realized using a heterogeneous Pd(II)/POP-GIEC catalyst, imine-linked, crystalline, and porous organic polymer supporter modified by coordination of Pd(OAc)2 to its walls under mild conditions. Surprisingly, for the first time, modified POP-supported low reduction degree PdII catalysts were synthesized efficiently, and they were successfully used in semihydrogenation of terminal alkynes. The substrate scope was studied and included both unfunctionalized as well as functionalized substituents on the para, ortho, and meta position of aromatic alkynes. The substrate having a substituent with the functionality of fluoro protected at the meta position was semihydrogenated with a high alkyne conversion of 100% and olefin selectivity (up to 99%).
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
Chemical Science
·
2019
·Vol. 10
·期 12
·3556-3566
·
IF 9.556
Yanan Liu,Alan J. McCue,Pengfei Yang,Yufei He,Lirong Zheng,Xingzhong Cao,Yi Man,Junting Feng,James A. Anderson,Dianqing Li
The impregnation method is commonly employed to prepare supported multi-metallic catalysts but it is often difficult to achieve homogeneous and stable alloy structures. In this work, we revealed the dependence of alloying behavior on the support morphology by fabricating Ni–Cu over different shaped CeO2. Specifically, nanocube ceria favoured the formation of monometallic Cu and Ni-rich phases whereas polycrystalline and nanorod ceria induced the formation of a mixture of Cu-rich alloys with monometallic Ni. Surprisingly, nanopolyhedron (NP) ceria led to the generation of homogeneous Ni–Cu nanoalloys owing to the equivalent interactions of Ni and Cu species with CeO2 (111) facets which exposed relatively few coordinative unsaturated sites. More importantly, a strong interfacial effect was observed for Ni–Cu/CeO2-NP due to the presence of CeOx adjacent to metal sites at the interface, resulting in excellent stability of the alloy structure. With the aid of CeOx, NiCu nanoalloys showed outstanding catalytic behaviour in acetylene and hexyne hydrogenation reactions. This study provides valuable insights into how fully alloyed and stable catalysts may be prepared by tailoring the support morphology while still employing a universal impregnation method.
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
危险品化学品经营许可证（带存储）