ACS Catalysis
·
2024
·
IF 11.3
Mei-Yao Wu,Shan-Qing Li,Wei-Wei Wang,Chun-Jiang Jia
The structures of active components in practical solid catalysts are seldom homogeneous, which makes it challenging to explore the synergistic effect among the complex catalyst components in heterogeneous catalysis. The active structure of Cu-based catalysts, which are widely used in water gas shift reactions and other important industrial reactions, has been debated. This work prepared Cu–MgO catalysts with the copresence of Cu particles and Cu atoms to investigate the synergistic effects of these Cu species. We found that the Cu nanoparticles served to adsorb and activate the reactant molecule of CO, while the atomic Cu species at the surface of the MgO lattice might exist as the Mg2Cu2–Ov site for water dissociation. The presence of surface-substituted Cu atoms modulated the reactivity of adjacent oxygen vacancy in the MgO surface, enhanced the ability of H2O dissociation to form reactive –OH species, and allowed the oxygen vacancies to recycle, contributing to the continuation of the reaction. A volcano-type relation of catalytic performance versus Cu0/Cu2+ ratio has been established, revealing the existence of synergy between Cu particles and Cu atoms. In addition, due to this synergistic effect, the optimized Cu–MgO catalyst shows a very high activity with a CO conversion rate of 1119 μmolCO gCu–1 s–1 at 300 °C. This work revealed the synergistic effect of different Cu species in the Cu–MgO catalysts, which was important for unraveling the contribution of complex components to catalytic performance.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2014
·Vol. 111
·期 2
·633-645
·
IF 0.983
Yue Chuan-Jun,Gu Li-Ping,Su Yang,Zhu Shao-Ping
Cu/MgO and MgO nested on the surface of Raney Cu were prepared by a wet-mixing method and used as catalyst for glycerol hydrogenolysis. The texture of Raney Cu/MgO was characterized by X-ray diffraction and transmission electron microscopy, Brunauer–Emmett–Teller, and CO 2 -temperature-programmed desorption techniques. Results indicated that MgO was well dispersed in the pores of Raney Cu. Moreover, Raney Cu with large specific surface area had a larger contact surface for MgO, and a new phase of Cu–MgO was produced. Glycerol hydrogenolysis was selectively catalyzed under the synergistic effect of Cu and MgO in Cu/MgO catalyst. Under the moderate conditions of 180 °C and 1 MPa H 2 , the conversion of glycerol was 36.2 wt% and the selectivity for 1,2-propanediol was ~85 wt% when chemical equilibrium.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2021
·
IF 5.816
Qiangqiang Xue,Zhengwen Li,Zhao Jiang,Meng Chen,Yujun Wang,Binhang Yan,Guangsheng Luo
Steam reforming (SR) is a process for converting transportation fuels into hydrogen-rich gas, which can be fed to SOFCs for on-board power supplies. Herein, we prepare Mg x Ni 1-x O (0.5
研究领域:
能源化学
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
Desalination and Water Treatment
·
2015
·
IF 1.173
Jun Chen,Shuanghong Tian,Lingjun Kong,Yuting Tu,Jiang Lu,Ya Xiong
An integrated heterogeneous catalytic ozonation and membrane separation system was studied for continuous degradation of refractory organic pollutants in water. MgO nanosheets with dominant (111) facets showed large amounts of medium and strong basic sites due to the particular structure of alternating monolayers of exclusively oxygen and exclusively magnesium atoms. MgO(111) acted as the ozonation catalyst for the first time, it was found that efficient degradation of nitrobenzene was achieved with 25.0 mmol/L of MgO(111) catalysts in a wide pH range of 4.0–12.0. In view of practical application, engineering problems to recover fine size catalysts from the treated water were resolved by applying membrane separation technology in the system. Experimental results showed that the membrane could successfully intercept MgO(111) particles in the reactor by the synergistic cooperative sieving of the bare and dynamic membranes. The long-term continuous experiments demonstrated that the removal rate of nitrobenzene could maintain over 90% with a constant flux of 3.92 L m−2 min−1 during the 24 h operation. The continuous system provides a new method for practical application of heterogeneous catalytic ozonation to remove refractory organic pollutants.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
ACS Catalysis
·
2024
·
IF 11.3
Xiaohong Ren,Qian Qiang,Zhuohua Sun,Ting Wei,Xiaoqiang Yu,Zeming Rong,Changzhi Li
This work demonstrates the upgrading of lignin-derived monomers through a cascade demethoxylation, aqueous-phase reforming reaction, eliminating the need for external hydrogen supply. The core of this research lies in the use of neat water as both reaction medium and the hydrogen donor over a multifunctional Ni/MgO catalyst, which is responsible for water splitting, aqueous-phase reforming of in situ generated methanol, and selective cleavage of the C–O bond, finally establishing an efficient one-pot approach achieving a high yield of phenols. Reaction mechanism studies proved that the initial H* source came from water by its splitting on the surface of the Ni/MgO catalyst, which triggered the fracture of the aromatic ether bond to afford phenols and CH3O*. The subsequent aqueous-phase reforming of CH3O* and OH* generated more hydrogen and further accelerated the hydrodeoxygenation (HDO) process. A high conversion of 87.8% with a selectivity of 88.9% for phenol could be achieved at 190 °C from guaiacol. Thanks to the interesting water-splitting mechanisms and strong metal–support interaction (SMSI), Ni/MgO exhibited significantly enhanced stability compared to the previously reported nanoporous Ni catalysts. Further, with real lignin as the substrate, 16.3 wt % combined yield of phenol and 4-methylphenol could be acquired under optimized conditions. Overall, this “H2-free” approach offers a promising alternative to conventional biorefinery processes, addressing the challenges of hydrogen sourcing and economic feasibility.
研究领域:
催化化学
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生物质能
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可再生能源
✓ 已验证
产品关联
DOI
高影响因子
Nano Energy
·
2025
·
IF 17.1
Zhao Sun,Huicai Wang,Xingxu Wang,Riguang Zhang,Zhiqiang Sun
Sorption-enhanced steam reforming of methanol (SE-SRM) offers a promising route for high-quality hydrogen production with in situ CO 2 capture; however, achieving an optimal balance between catalytic activity and CO 2 uptake capability, while ensuring catalyst stability, remains a significant challenge. In this study, a series of Zr-doped (0 wt%, 5 wt%, 15 wt%, 25 wt%) Cu-MgO catalytic sorbents are synthesized for SE-SRM. At 180℃, the hydrogen concentration and yield reach nearly 100 % and 10.35 μmol·g −1 ·s −1 . Moreover, the catalytic sorbent basically retains its catalytic activity and CO 2 uptake capacity after 30 cycles with merely slight deactivation. Results demonstrate that the doped Zr, presents as tetragonal ZrO 2 , enhances metal-support interactions with the formation of a Cu-O-Zr interfacial structure, promoting Cu nanocluster dispersion and altering the Cu + /Cu 0 distributions. Zr doping also enables the modulation of the medium-strong basic sites. Moreover, the AFM and TEM confirmed the formation of high-roughness MgO surface on the substrate, thereby facilitating CO 2 diffusion and adsorption. DFT calculation results further confirm the advantages of Zr-doped Cu-MgO catalytic sorbents due to its stronger capability on CH 3 OH activation and CO 2 adsorption.
研究领域:
催化化学
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材料科学
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能源化学
✓ 已验证
DOI
高影响因子
Scientific Reports
·
2021
·Vol. 11
·期 1
·1-17
·
IF 4.38
Liu Ju,Chen Fei,Yang Wenbing,Guo Jianjun,Xu Guangwen,Jia Fenglei,Shi Lei
The activities of various MgO catalysts, which were prepared from different methods such as hydration synthesis, thermal decomposition, combustion, sol–gel and co-precipitation, were conducted in dimethyl carbonate (DMC) synthesis via transesterification of ethylene carbonate with methanol. MgO-P-Na 2 CO 3 -3.14 synthesized by the excess Na 2 CO 3 precipitation compared the best catalytic activity and stability, which could be reused for seven times without obvious deactivation. The DMC yield was as high as 69.97% at 68 °C. The transesterification reaction could be separated into two steps, and the samples obtained by NaOH precipitant exhibited better ring-opening capability, while the catalysts acquired by Na 2 CO 3 precipitant displayed superior transesterification ability. The structure-performance relationship was evaluated by multiple characterization methods. The results indicated that the as-synthesized catalyst derived from dried precursors with more crystalline magnesium carbonate was favorable for the promotion of DMC yield, and MgO-P-Na 2 CO 3 -3.14 with more Mg-O pairs, which were the active center for the transesterification of 2-hydroxyethyl methyl carbonate (HEMC) intermediate with methanol, resulted in more moderately basic sites left that was in accordance with the DMC yield variation. MgO-P-Na 2 CO 3 -3.14 with greater BET surface area and mesopore volume, relative low surface oxygen content and larger moderately basic sites amount compared the excellent activity in DMC synthesis.
研究领域:
化学工程
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催化材料科学
✓ 已验证
DOI
PubMed
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 25
·15477-15485
·
IF 3.361
Fengjiao Li,Liguo Wang,Shuang Xu,Shuting Liang,Ningning Zhang
Developing cost-effective, high-efficiency and heterogeneous catalysts is of prime importance for the green synthesis of diethyl carbonate (DEC) from ethyl carbamate (EC) and ethanol. Herein, a series of MgO/γ-Al2O3 catalysts were readily fabricated by an impregnation method for DEC synthesis from EC and ethanol. The activities of the as-prepared MgO/γ-Al2O3 catalysts as well as the individual MgO or γ-Al2O3 were first tested in the batch reactor. Among the investigated samples, the MgO/γ-Al2O3 with a MgO loading of 10 wt% (denoted as 10% MgO/γ-Al2O3) exhibited the largest amount of stronger basic sites, and the highest activities with EC conversion of 41.8% and DEC yield of 30.4%, respectively. Furthermore, the DEC yield was greatly boosted to 52.1% with a high DEC selectivity of 93.8% over the 10% MgO/γ-Al2O3 catalyst under the optimized reaction conditions in the fixed bed reactor, outperforming most of the reported catalysts.
研究领域:
催化化学
·
绿色化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Zijie Lu,Haokun Bai,Lanlan Liang,Shuo Chen,Hongtao Yu,Xie Quan
Heterogeneous catalytic ozonation (HCO) enables the destruction of organic pollutants in wastewater via oxidation by powerful hydroxyl radicals (·OH). However, the availability of short‐lived ·OH in aqueous bulk is low in practical treatment scenarios due to mass transfer limitations and quenching of water constituents. Herein, we overcome these challenges by loading MgO catalysts inside the pores of a tubular ceramic membrane (denoted as CCM) to confine ·OH within the nanopores and achieve efficient pollutant removal. When the pore size of the membrane was reduced from 1000 to 50 nm, the removal of ibuprofen (IBU) by CCM was increased from 49.6 % to 90.2 % due to the enhancement of ·OH enrichment in the nanospace. In addition, the CCM exhibited high catalytic activity in the presence of co-existing ions and over a wide pH range, as well as good self-cleaning ability in treating secondary wastewater. The experimental results revealed that ·OH were the dominant reactive oxygen species (ROS) in pollutant degradation, while surface hydroxyl groups were active sites for the generation of ·OH via ozone decomposition. This work provides a promising strategy to enhance the utilization of ·OH in HCO for the efficient degradation of organic pollutants in wastewater under spatial confinement.
研究领域:
环境科学
·
催化化学
·
废水处理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ORGANIC PROCESS RESEARCH & DEVELOPMENT
·
2018
·
IF 3.584
Jie Zhang,Lei Wang,Chuang Li,Shaohua Jin,Changhai Liang
Direct selective hydrogenolysis of dibenzofuran (DBF) derived from coal and shale oil to a value-added chemical, ortho-phenylphenol (OPP), with high selectivity (80%) and yield (48%) has been achieved over Pt/MgO at 400 °C and 1.0 MPa by controlling the C–O bond cleavage as well as minimizing the extent of hydrogenation of aromatic rings. Meanwhile, Pt/SiO2, Pt/Al2O3, and Pt/MgO/Al2O3 catalysts were used for the DBF hydrogenolysis and showed lower selectivity for OPP. The influence of reaction parameters has been studied to unveil the optimal reaction conditions. And the phenomenon of OPP dehydrogenation is found over various catalysts for the hydrogenation reaction of OPP. Extensive reactions and catalyst characterizations demonstrated that the OPP selectivity and the dehydrogenation of OPP to DBF follows the order of supports basicity: MgO-900 > MgO > SiO2 > MgO/Al2O3 > Al2O3, which shows that the acid–base properties of supports impact the adsorption and desorption behaviors of DBF and OPP, and results in the disparity of OPP selectivity and the dehydrogenation of OPP. Finally, a plausible reaction pathway and mechanistic understanding are proposed.
研究领域:
催化化学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY CONVERSION AND MANAGEMENT
·
2015
·
IF 4.38
Jinxing Long,Shiyang Shu,Qingyun Wu,Zhengqiu Yuan,Tiejun Wang,Ying Xu,Xinghua Zhang,Qi Zhang,Longlong Ma
Selective production of cyclohexanol from renewable lignin derived phenolic has been presented using the cost-efficient catalyst Ni/MgO which shows excellent catalytic activity in the hydrogenation reaction and dehydroxylation inhibition. Guaiacol, one of the most abundant lignin depolymerization products, was selected as the model compound. The hydrogenation performance of guaiacol was investigated over various catalysts. The effect of the reaction parameters was also studied. The results showed that guaiacol could be efficiently converted to cyclohexanol, which is a highly value-added precursor and additive for bio-fuel that is generally obtained from unsustainable fossil resources. Under the mild condition (160 °C, 3 h and 3 MPa H 2 ), more than 97.74% of guaiacol conversion with 100% cyclohexanol selectivity can be achieved in the presence of 20% Ni/MgO. Intensive catalyst characterization demonstrated that the efficient promotion effect of the base carrier for the Ni active center was responsible for efficient guaiacol conversion and selective cyclohexanol production. Furthermore, the Ni/MgO catalyst showed excellent recyclability, where no significant activity loss was observed even after four runs. Moreover, the reaction pathway and the catalytic mechanism are proposed.
研究领域:
化学工程
·
催化科学
·
可再生能源
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2023
·
IF 4.7
Kai Sun,Yuewen Shao,Cong Ming,Mengjiao Fan,Huailin Fan,Lijun Zhang,Shu Zhang,Yi Wang,Guozhu Chen,Xun Hu
Impregnation is a traditional method for preparing heterogeneous catalysts, which typically includes impregnation, calcination and reduction steps. In this study, catalyst preparation was combined with its use in catalytic hydrogenation for avoiding ex-situ catalyst-synthesis. Specifically, Cu/MgO were prepared by simply mixing CuSO 4 , MgO and the reactant to be hydrogenated such as levulinic acid (LA) or ethyl levulinate (EL) in ethanol with hydrogen. Heating of the mixture to 160 °C could obtain both synthesized Cu/MgO and hydrogenation product of gamma-valerolactone (GVL) (highest yield: 99.9%). The formation of Cu/MgO catalyst proceeded via the steps of fixing Cu 2+ by reacting with the basic sites of MgO to form Cu(OH) 2 . The metastable Cu(OH) 2 decomposed to form CuO that was reduced to Cu for catalyzing conversion of LA/EL to GVL. Such a method is very simple and applicable to prepare varied types of Cu-based catalyst by changing copper salts and supports of varied alkalinity.
研究领域:
催化
·
化学工程
·
可再生能源
✓ 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）