Preparation, microstructure characterization and catalytic performance of Cu/ZnO and ZnO/Cu composite nanoparticles for liquid phase methanol synthesis

In recent years, metal–organic frameworks (MOFs) have received increasing attention as selective oxidation catalysts and supports for their construction. In this short review paper, we survey recent findings concerning use of MOFs in heterogeneous liquid-phase selective oxidation catalysis with the green oxidant–aqueous hydrogen peroxide. MOFs having outstanding thermal and chemical stability, such as Cr(III)-based MIL-101, Ti(IV)-based MIL-125, Zr(IV)-based UiO-66(67), Zn(II)-based ZIF-8, and some others, will be in the main focus of this work. The effects of the metal nature and MOF structure on catalytic activity and oxidation selectivity are analyzed and the mechanisms of hydrogen peroxide activation are discussed. In some cases, we also make an attempt to analyze relationships between liquid-phase adsorption properties of MOFs and peculiarities of their catalytic performance. Attempts of using MOFs as supports for construction of single-site catalysts through their modification with heterometals will be also addressed in relation to the use of such catalysts for activation of H2O2. Special attention is given to the critical issues of catalyst stability and reusability. The scope and limitations of MOF catalysts in H2O2-based selective oxidation are discussed.

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MODELING OF A LIQUID ENTRAINED REACTOR FOR LIQUID PHASE METHANOL SYNTHESIS PROCESS

Fuel Science and Technology International ◽

10.1080/08843759208905360 ◽

1992 ◽

Vol 10 (9) ◽

pp. 1501-1521 ◽

Cited By ~ 9

Author(s):

P vijayaraghavan ◽

Conrad J. Kulik ◽

Sunggyu Lee

Keyword(s):

Liquid Phase ◽

Methanol Synthesis ◽

Synthesis Process

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Enhancement of stability and activity of Cu/ZnO/Al2O3 catalysts by microwave irradiation for liquid phase methanol synthesis

Fuel ◽

10.1016/j.fuel.2012.11.003 ◽

2013 ◽

Vol 106 ◽

pp. 178-186 ◽

Cited By ~ 21

Author(s):

Zhong Li ◽

Shaowei Yan ◽

Hui Fan

Keyword(s):

Liquid Phase ◽

Microwave Irradiation ◽

Methanol Synthesis

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How basic properties of MgO-based mixed oxides affect the catalytic performance in gas-phase and liquid-phase methylation of m-cresol

Oxide Based Materials - New sources, novel phases, new applications - Studies in Surface Science and Catalysis ◽

10.1016/s0167-2991(05)80146-6 ◽

2005 ◽

pp. 167-177 ◽

Cited By ~ 9

Author(s):

F. Cavani ◽

L. Maselli ◽

D. Scagliarini ◽

C. Flego ◽

C. Perego

Keyword(s):

Liquid Phase ◽

Gas Phase ◽

Mixed Oxides ◽

Catalytic Performance ◽

Basic Properties

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Preformed Pd-Based Nanoparticles for the Liquid Phase Decomposition of Formic Acid: Effect of Stabiliser, Support and Au–Pd Ratio

Applied Sciences ◽

10.3390/app10051752 ◽

2020 ◽

Vol 10 (5) ◽

pp. 1752 ◽

Cited By ~ 2

Author(s):

Felipe Sanchez ◽

Ludovica Bocelli ◽

Davide Motta ◽

Alberto Villa ◽

Stefania Albonetti ◽

...

Keyword(s):

Liquid Phase ◽

Formic Acid ◽

Pd Nanoparticles ◽

Catalytic Performance ◽

Atomic Ratio ◽

Phase Decomposition ◽

Acid Effect ◽

Formic Acid Decomposition ◽

Structure Morphology

Hydrogen is one of the most promising energy carriers for the production of electricity based on fuel cell hydrogen technology. Recently, hydrogen storage chemicals, such as formic acid, have been proposed to be part of the long-term solution towards hydrogen economy for the future of our planet. Herein we report the synthesis of preformed Pd nanoparticles using colloidal methodology varying a range of specific experimental parameters, such as the amount of the stabiliser and reducing agent, nature of support and Pd loading of the support. The aforementioned parameters have shown to affect mean Pd particle size, Pd oxidation, atomic content of Pd on the surface as well as on the catalytic performance towards formic acid decomposition. Reusability studies were carried out using the most active monometallic Pd material with a small loss of activity after five uses. The catalytic performance based on the Au–Pd atomic ratio was evaluated and the optimum catalytic performance was found to be with the Au/Pd atomic ratio of 1/3, indicating that the presence of a small amount of Pd is essential to promote significantly Au activity for the liquid phase decomposition of formic acid. Thorough characterisation has been carried out by means of XPS, SEM-EDX, TEM and BET. The observed catalytic performance is discussed in terms of the structure/morphology and composition of the supported Pd and Au–Pd nanoparticles.

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Characterization and catalytic performance of basaltic dust as an efficient catalyst in the liquid‐phase esterification of acetic acid with n ‐butanol

Journal of the Chinese Chemical Society ◽

10.1002/jccs.201800397 ◽

2019 ◽

Vol 66 (7) ◽

pp. 725-733 ◽

Cited By ~ 3

Author(s):

Abd El‐Aziz A. Said ◽

Mohamed Th. S. Heikal ◽

Mohamed N. Goda

Keyword(s):

Acetic Acid ◽

Liquid Phase ◽

Catalytic Performance ◽

Efficient Catalyst

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Catalytic Performance of Nitrogen-Doped Activated Carbon Supported Pd Catalyst for Hydrodechlorination of 2,4-Dichlorophenol or Chloropentafluoroethane

Molecules ◽

10.3390/molecules24040674 ◽

2019 ◽

Vol 24 (4) ◽

pp. 674 ◽

Cited By ~ 2

Author(s):

Haodong Tang ◽

Bin Xu ◽

Meng Xiang ◽

Xinxin Chen ◽

Yao Wang ◽

...

Keyword(s):

Activated Carbon ◽

Liquid Phase ◽

Gas Phase ◽

Nitrogen Doping ◽

Catalyst Surface ◽

Catalytic Performance ◽

Atomic Ratio ◽

Pd Catalyst ◽

Nitrogen Doped ◽

The Stability

Nitrogen-doped activated carbon (N-AC) obtained through the thermal treatment of a mixture of HNO3-pretreated activated carbon (AC) and urea under N2 atmosphere at 600 °C was used as the carrier of Pd catalyst for both liquid-phase hydrodechlorination of 2,4-dichlorophenol (2,4-DCP) and gas-phase hydrodechlorination of chloropentafluoroethane (R-115). The effects of nitrogen doping on the dispersion and stability of Pd, atomic ratio of Pd/Pd2+ on the surface of the catalyzer, the catalyst’s hydrodechlorination activity, as well as the stability of N species in two different reaction systems were investigated. Our results suggest that, despite no improvement in the dispersion of Pd, nitrogen doping may significantly raise the atomic ratio of Pd/Pd2+ on the catalyst surface, with a value of 1.2 on Pd/AC but 2.2 on Pd/N-AC. Three types of N species, namely graphitic, pyridinic, and pyrrolic nitrogen, were observed on the surface of Pd/N-AC, and graphitic nitrogen was stable in both liquid-phase hydrodechlorination of 2,4-DCP and gas-phase hydrodechlorination of R-115, with pyridinic and pyrrolic nitrogen being unstable during gas-phase hydrodechlorination of R-115. As a result, the average size of Pd nanocrystals on Pd/N-AC was almost kept unchanged after liquid-phase hydrodechlorination of 2,4-DCP, whereas crystal growth of Pd was clearly observed on Pd/N-AC after gas-phase hydrodechlorination of R-115. The activity test revealed that Pd/N-AC exhibited a much better performance than Pd/AC in liquid-phase hydrodechlorination of 2,4-DCP, probably due to the enhanced stability of Pd exposed to the environment resulting from nitrogen doping as suggested by the higher atomic ratio of Pd/Pd2+ on the catalyst surface. In the gas-phase hydrodechlorination of R-115, however, a more rapid deactivation phenomenon occurred on Pd/N-AC than on Pd/AC despite a higher activity initially observed on Pd/N-AC, hinting that the stability of pyridinic and pyrrolic nitrogen plays an important role in the determination of catalytic performance of Pd/N-AC.

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