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You searched for: Journal name Journal of catalysis Remove constraint Journal name: Journal of catalysis Subject term active sites Remove constraint Subject term: active sites Subject term carbon Remove constraint Subject term: carbon
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1. A salt induced gelatin crosslinking strategy to prepare Fe-N doped aligned porous carbon for efficient oxygen reduction reaction catalysts and high-performance supercapacitors

Author:
Pengfei Tian; Yanhui Wang; Wei Li; Shiwei Song; Shuyu Zhou; Hongwei Gao; Hanqing Xu; Xueqing Tian; Jianbing Zang
Source:
Journal of catalysis 2020 v.382 pp. 109-120
ISSN:
0021-9517
Subject:
active sites; calcium chloride; capacitance; carbon; catalysts; catalytic activity; crosslinking; durability; electrochemical capacitors; electrochemistry; electrodes; electrolytes; gelatin; microrelief; platinum; sodium chloride
Abstract:
... The preparation of low-cost, high-efficiency and stable oxygen reduction reaction (ORR) catalysts is highly anticipated but remains a challenge. Herein, a novel strategy of CaCl₂ solution inducing gelatin crosslinking and acting as aligned pore template was put forward for preparation of Fe-N doped aligned hierarchical porous carbon. Furthermore, the microtopography and length of aligned pore can ...
DOI:
10.1016/j.jcat.2019.12.011

2. A site-sensitive quasi-in situ strategy to characterize Mo/HZSM-5 during activation

Author:
Ina Vollmer; Nikolay Kosinov; Ágnes Szécsényi; Guanna Li; Irina Yarulina; Edy Abou-Hamad; Andrei Gurinov; Samy Ould-Chikh; Antonio Aguilar-Tapia; Jean-Louis Hazemann; Evgeny Pidko; Emiel Hensen; Freek Kapteijn; Jorge Gascon
Source:
Journal of catalysis 2019 v.370 pp. 321-331
ISSN:
0021-9517
Subject:
active sites; benzene; carbon; carbon monoxide; catalysts; chemical composition; geometry; methane; molybdenum; nanoparticles; nuclear magnetic resonance spectroscopy; oxidation; spectral analysis; stable isotopes; zeolites
Abstract:
... The active sites on the methane dehydroaromatization (MDA) catalyst Mo/HZSM-5 are very hard to characterize, because they are present in various geometries and sizes and only form under reaction conditions with methane at 700 °C. To address these issues an experimental strategy is presented that enables distinguishing different active sites for MDA present on Mo/HZSM-5 and helps determining the Mo ...
DOI:
10.1016/j.jcat.2019.01.013

3. Active and stable Fe-based catalyst, mechanism, and key role of alkali promoters in ammonia synthesis

Author:
Walid Al Maksoud; Rohit K. Rai; Natalia Morlanés; Moussab Harb; Rafia Ahmad; Samy Ould-Chikh; Dalaver Anjum; Mohamed N. Hedhili; Bedour E. Al-Sabban; Khalid Albahily; Luigi Cavallo; Jean-Marie Basset
Source:
Journal of catalysis 2021 v.394 pp. 353-365
ISSN:
0021-9517
Subject:
Gibbs free energy; activation energy; active sites; alkali metals; ammonia; carbon; carbon dioxide; catalysts; catalytic activity; emissions; iron; leaves; methane production; nitrogen; pressure; pyrolysis; synthesis
Abstract:
... Worldwide NH₃ production reached 0.18 Gton in 2019, and 1–2% of the global CO₂ emissions are due to large-scale NH₃ synthesis (1 billion tons of CO₂ / year). A catalyst for ammonia synthesis has been obtained by pyrolysis of iron phthalocyanine (FePc) precursor under N₂, followed by impregnation with alkali metals (Na, Li, K, and Cs) and H₂ treatment. Characterization (XPS, XRD, HR-TEM, ICP-OES, T ...
DOI:
10.1016/j.jcat.2020.10.031

4. Active sites and mechanism on nitrogen-doped carbon catalyst for hydrogen evolution reaction

Author:
Gui-fa Long; Kai Wan; Ming-yao Liu; Zhen-xing Liang; Jin-hua Piao; Panagiotis Tsiakaras
Source:
Journal of catalysis 2017 v.348 pp. 151-159
ISSN:
0021-9517
Subject:
active sites; carbon; catalysts; desorption; electrochemistry; hydrogen production; nitrogen; nitrogen content; pH
Abstract:
... The nature of active sites and mechanism of hydrogen evolution reaction (HER) on the nitrogen-doped carbon catalyst is extensively investigated, by combining physicochemical and electrochemical methods. Two carbon catalysts, with the same chemical nature but different nitrogen content, are employed in this investigation. Electrochemical methods are applied to investigate the electrochemical behavi ...
DOI:
10.1016/j.jcat.2017.02.021

5. Aminated poly(ethylene glycol) methacrylate resins as stable heterogeneous catalysts for the aldol reaction in water

Author:
Anton De Vylder; Jeroen Lauwaert; Jeriffa De Clercq; Pascal Van Der Voort; Christopher W. Jones; Joris W. Thybaut
Source:
Journal of catalysis 2020 v.381 pp. 540-546
ISSN:
0021-9517
Subject:
Fourier transform infrared spectroscopy; Lewis bases; acetone; active sites; batch systems; carbon; catalysts; catalytic activity; chlorination; ethylenediamines; hexane; hydrogels; hydrolysis; leaching; methylamine; moieties; nuclear magnetic resonance spectroscopy; polyethylene glycol; polymerization; resins; secondary amines; silica; solvents; stable isotopes
Abstract:
... Amine functionalized silicas have frequently been investigated as potential aldol reaction catalysts. However, active site leaching due to hydrolysis cannot be avoided, limiting the long-term stability of these catalysts in aqueous aldol reactions. Therefore, novel catalysts based on an organic resin have been developed starting from a suspension polymerized poly(ethylene glycol) methacrylate (PEG ...
DOI:
10.1016/j.jcat.2019.11.027

6. Atomically dispersed Ptn+ species as highly active sites in Pt/In2O3 catalysts for methanol synthesis from CO2 hydrogenation

Author:
Zhe Han; Chizhou Tang; Jijie Wang; Landong Li; Can Li
Source:
Journal of catalysis 2021 v.394 pp. 236-244
ISSN:
0021-9517
Subject:
active sites; carbon; carbon dioxide; catalysts; hydrogen; hydrogenation; methanol; nanoparticles; platinum; renewable energy sources; working conditions
Abstract:
... Hydrogenation of CO₂ into methanol using the H₂ produced from renewable energy is a promising way for carbon capture and utilization. Therefore, the methanol synthesis catalysts with high methanol selectivity are highly desired. In this work, we found that the methanol selectivity of In₂O₃ catalyst can be significantly enhanced by introducing a small amount of Pt. Methanol selectivity can be incre ...
DOI:
10.1016/j.jcat.2020.06.018

7. Boosting carbon dioxide electroreduction to C1 feedstocks via theory-guided tailoring oxygen defects in porous tin-oxide nanocubes

Author:
Haichuan He; Kang Liu; Kaixin Liang; Abdulhadi Mustapha; Zheng Wang; Linlin Wu; Congcheng Yang; Liu Deng; Shaojun Guo; You-Nian Liu
Source:
Journal of catalysis 2020 v.385 pp. 246-254
ISSN:
0021-9517
Subject:
active sites; carbon; carbon dioxide; catalysts; density functional theory; electrochemistry; feedstocks; flue gas; hydrogen; nanomaterials; oxygen; tin dioxide
Abstract:
... Metal-oxide catalysts have great potential in efficient CO₂ electroreduction (CO₂ER). Unfortunately, many catalysts exhibit limited selectivity for carbon products at the high current density. Here, density functional theory is applied to analyzethe active sites on SnO₂ matrix surface. The theoretical analysis indicates that the elimination of oxygen atoms from SnO₂ matrix can significantly improv ...
DOI:
10.1016/j.jcat.2020.03.015

8. CO oxidation on inverse Fe₂O₃/Au(111) model catalysts

Author:
Ting Yan; Daniel W. Redman; Wen-Yueh Yu; David W. Flaherty; José A. Rodriguez; C. Buddie Mullins
Source:
Journal of catalysis 2012 v.294 no. pp. 216-222
ISSN:
0021-9517
Subject:
active sites; carbon; carbon monoxide; catalysts; catalytic activity; ferric oxide; gold; nanoparticles; oxidation; oxygen; temperature
Abstract:
... CO oxidation is studied at pressures between 4 and 100Torr and temperatures from 400K to 670K on inverse model catalysts made of Fe₂O₃ nanoclusters grown on a Au(111) single crystal surface. The addition of Fe₂O₃ nanoclusters transformed the inert Au(111) single crystal into an active catalyst for CO oxidation. The catalytic activity increases with iron oxide coverage initially and then decreases ...
DOI:
10.1016/j.jcat.2012.07.024

9. Catalytic decomposition of H2O2 over a Au/carbon catalyst: A dual intermediate model for the generation of hydroxyl radicals

Author:
Xue-jing Yang; Peng-fei Tian; Hua-lin Wang; Jing Xu; Yi-fan Han
Source:
Journal of catalysis 2016 v.336 pp. 126-132
ISSN:
0021-9517
Subject:
activation energy; active sites; carbon; catalysts; cytotoxicity; gold; hydrogen peroxide; hydroxyl radicals; models; nanogold; water treatment
Abstract:
... The generation of hydroxyl radicals (HO) by H2O2 decomposition over solid catalysts (a Fenton-like reaction) will play an important role in the design of new processes for water treatment. More specifically, the understanding of H2O2 decomposition on Au nanoparticles (NPs) is crucial for the optimization of the structure of active sites and the evaluation of cytotoxicity of Au NPs. Here, the kinet ...
DOI:
10.1016/j.jcat.2015.12.029

10. Chemical looping methane partial oxidation: The effect of the crystal size and O content of LaFeO₃

Author:
Oana Mihai; De Chen; Anders Holmen
Source:
Journal of catalysis 2012 v.293 no. pp. 175-185
ISSN:
0021-9517
Subject:
absorption; active sites; carbon; catalysts; combustion; energy; iron; methane; oxygen; spectroscopy; synthesis gas
Abstract:
... The site requirements for the methane total combustion, partial oxidation, and decomposition on LaFeO₃ perovskite catalysts during the chemical looping process were addressed by a kinetic study through varying the O content and the crystal size. The exchange between the surface oxygen and lattice oxygen is rapid, and the active sites of Fe associated with the surface oxygen are highly dynamic in n ...
DOI:
10.1016/j.jcat.2012.06.022

11. Co-precipitated Fe-Zr catalysts for the Fischer-Tropsch synthesis of lower olefins (C2O ∼ C4O): Synergistic effects of Fe and Zr

Author:
Zixuan Ma; Chenliang Zhou; Danmei Wang; Yaxiong Wang; Wenxiu He; Yisheng Tan; Quansheng Liu
Source:
Journal of catalysis 2019 v.378 pp. 209-219
ISSN:
0021-9517
Subject:
Fischer-Tropsch reaction; Raman spectroscopy; X-ray diffraction; X-ray photoelectron spectroscopy; active sites; adsorption; alkenes; carbon; carbon monoxide; catalysts; catalytic activity; coprecipitation; desorption; hematite; hydrogen; iron; nanomaterials; synergism; synthesis gas; zirconium; zirconium oxide
Abstract:
... Synthesis of lower olefins using syngas (H2/CO) in a fixed-bed reactor under 1.0 MPa, WHSV = 3 NLH2/CO·gFe-1·h-1 (WHSV = 3 NLH2/CO·gcat-1·h-1 for Zrp), H2/CO = 2 was investigated over a series of Fe-based catalysts with Zr as the promoter. The catalysts were prepared by co-precipitation (Fe and Zr) and K was impregnated into the precipitate. The prepared catalysts with different Zr/Fe mol ratio (Z ...
DOI:
10.1016/j.jcat.2019.08.037

12. Co-precipitated Fe-Zr catalysts for the Fischer-Tropsch synthesis of lower olefins (C2O∼C4O): Synergistic effects of Fe and Zr

Author:
Zixuan Ma; Chenliang Zhou; Danmei Wang; Yaxiong Wang; Wenxiu He; Yisheng Tan; Quansheng Liu
Source:
Journal of catalysis 2019 pp. -
ISSN:
0021-9517
Subject:
Fischer-Tropsch reaction; Raman spectroscopy; X-ray diffraction; X-ray photoelectron spectroscopy; active sites; adsorption; alkenes; carbon; carbon monoxide; catalysts; catalytic activity; coprecipitation; desorption; hematite; hydrogen; iron; nanomaterials; synergism; synthesis gas; zirconium; zirconium oxide
Abstract:
... Synthesis of lower olefins using syngas (H2/CO) in a fixed-bed reactor under 1.0 MPa, WHSV = 3NLH2/CO·gFe-1·h-1(WHSV = 3NLH2/CO·gcat-1·h-1 for Zrp), H2/CO=2 was investigated over a series of Fe-based catalysts with Zr as the promoter. The catalysts were prepared by co-precipitation (Fe and Zr) and K was impregnated into the precipitate. The prepared catalysts with different Zr/Fe mol ratio (Zr0, Z ...
DOI:
10.1016/j.jcat.2019.07.030

13. Comparison of mechanistic understanding and experiments for CO methanation over nickel

Author:
T.L. Wind; H. Falsig; J. Sehested; P.G. Moses; T.T.M. Nguyen
Source:
Journal of catalysis 2016 v.342 pp. 105-116
ISSN:
0021-9517
Subject:
active sites; carbon; carbon monoxide; catalysts; catalytic activity; data collection; density functional theory; hydrogen; hydrogenation; kinetics; methane production; models; nickel; reaction mechanisms; temperature
Abstract:
... A reaction mechanism based on Density Functional Theory (DFT) calculated energies was built using the Ni(211) step as representative for the active sites in Ni-based methanation catalysts and an analytical kinetic model based on two rate determining steps was used to evaluate a comprehensive experimental dataset over a wide range of conditions.Micro-kinetic analysis by means of the degree of rate ...
DOI:
10.1016/j.jcat.2016.07.014

14. Correlation of Pt–Re surface properties with reaction pathways for the aqueous-phase reforming of glycerol

Author:
Liang Zhang; Ayman M. Karim; Mark H. Engelhard; Zhehao Wei; David L. King; Yong Wang
Source:
Journal of catalysis 2012 v.287 no. pp. 37-43
ISSN:
0021-9517
Subject:
X-ray photoelectron spectroscopy; acidity; active sites; alkanes; ammonia; carbon; catalysts; desorption; glycerol; hydrogen; models; nanoparticles; oxidation
Abstract:
... The surface properties of Pt–Re catalytic nanoparticles supported on carbon following exposure to a hydrogen reducing environment and subsequent hydrothermal conditions have been studied using in situ X-ray photoelectron spectroscopy (XPS) and ammonia temperature-programmed desorption (TPD). These properties have been correlated with the catalyst selectivity for the aqueous-phase reforming of glyc ...
DOI:
10.1016/j.jcat.2011.11.015

15. Direct synthesis of hydrogen peroxide from hydrogen and oxygen over yolk–shell nanocatalyst Pd@HCS with controlled Pd nanoparticle size

Author:
Peng Liu; Qian Lin; Hongyan Pan; Jingyun Zhao; Chenchen Zhao; Yaodan Wang
Source:
Journal of catalysis 2019 v.377 pp. 511-523
ISSN:
0021-9517
Subject:
active sites; carbon; catalysts; catalytic activity; cyclohexanes; heptane; hydrogen; hydrogen peroxide; iso-octanes; nanoparticles; oils; oxygen; palladium; polyethylene glycol; porosity; solvents; surfactants
Abstract:
... For conventional palladium-coated catalysts, some active sites of the Pd surface are blocked by a shell and all reactants and products are confined in the same channel for diffusion, which reduces the catalytic activity. To solve these problems, a different type of yolk–shell nanocatalyst were prepared to directly synthesize hydrogen peroxide (H2O2): Pd@HCS, with Pd nanoparticles as core and hollo ...
DOI:
10.1016/j.jcat.2019.07.044

16. Easy synthesis of three-dimensionally ordered macroporous La₁₋ₓKₓCoO₃ catalysts and their high activities for the catalytic combustion of soot

Author:
Junfeng Xu; Jian Liu; Zhen Zhao; Chunming Xu; Jianxiong Zheng; Aijun Duan; Guiyuan Jiang
Source:
Journal of catalysis 2011 v.282 no.1 pp. 1-12
ISSN:
0021-9517
Subject:
Fourier transform infrared spectroscopy; X-ray diffraction; X-ray photoelectron spectroscopy; active sites; carbon; catalysts; catalytic activity; combustion; energy-dispersive X-ray analysis; hydrogen; polymers; scanning electron microscopy; soot; titration; transmission electron microscopy
Abstract:
... Three-dimensionally ordered macroporous (3DOM) La₁₋ ₓKₓCoO₃ (x=0–0.3) perovskite-type oxide catalysts with large pore sizes and interconnected macroporous frameworks were successfully synthesized by a novel method of carboxy-modified colloidal crystal templates (CMCCT). The obtained catalysts were characterized by means of XRD, FT-IR, SEM, TEM, BET, XPS, and H₂ TPR. The detailed preparation proces ...
DOI:
10.1016/j.jcat.2011.03.024

17. Effect of potassium on the active phases of Fe catalysts for carbon dioxide conversion to liquid fuels through hydrogenation

Author:
Meital Amoyal; Roxana Vidruk-Nehemya; Miron V. Landau; Moti Herskowitz
Source:
Journal of catalysis 2017 v.348 pp. 29-39
ISSN:
0021-9517
Subject:
X-ray photoelectron spectroscopy; active sites; carbon; carbon dioxide; carbon monoxide; catalysts; fuels; hydrocarbons; hydrogenation; iron; liquids; methane production; models; nanocrystals; oxygen; potassium
Abstract:
... The effect of potassium was tested with unpromoted and K-promoted Fe-Al-O oxide and Fe5C2 carbide materials, formed during CO2 hydrogenation from Fe-Al-O spinel. Each one of the tested catalysts contained a single phase (oxide or carbide). 2wt% potassium enhanced the RWGS rate of reaction on the oxide phase tenfold compared with the unpromoted oxide. This correlated with increase of Fe²⁺/Fe³⁺ rati ...
DOI:
10.1016/j.jcat.2017.01.020

18. Effects of Brønsted-acid site proximity on the oligomerization of propene in H-MFI

Author:
Anton N. Mlinar; Paul M. Zimmerman; Fuat E. Celik; Martin Head-Gordon; Alexis T. Bell
Source:
Journal of catalysis 2012 v.288 no. pp. 65-73
ISSN:
0021-9517
Subject:
activation energy; active sites; aluminum; carbon; chemical analysis; cracking; desorption; dimerization; infrared spectroscopy; propylene; silicon; space and time; zeolites
Abstract:
... The oligomerization of propene was investigated over H-MFI zeolites with varying Si/Al ratios. For a constant space time per active site, the conversion of propene as well as the selectivity to products of different carbon number was affected by the density of the sites within the zeolite. In particular, as the Si/Al ratio decreased, corresponding to an increase in site proximity, the rate of olig ...
DOI:
10.1016/j.jcat.2012.01.002

19. Effects of the method of active site characterization for determining structure-sensitivity in Ag-catalyzed ethylene epoxidation

Author:
Benjamin T. Egelske; Wen Xiong; Haiying Zhou; John R. Monnier
Source:
Journal of catalysis 2022 v.410 pp. 221-235
ISSN:
0021-9517
Subject:
active sites; aluminum oxide; carbon; catalysts; catalytic activity; combustion; epoxidation reactions; ethylene; hydrogen; isomerization; olefin; oxygen; particle size; surface area; temperature; titration
Abstract:
... Catalysts have been prepared on a low surface area α-Al₂O₃ support used commercially for previous generation olefin epoxidation catalysts. Prescreening of the low surface area alumina (0.73 m²/g) indicated the absence of acid catalyzed isomerization of EO at an evaluation temperature of 210 °C. A 0.1 wt% Ag base material synthesized by incipient wetness impregnation of AgNO₃ was used as a base mat ...
DOI:
10.1016/j.jcat.2022.03.021

20. Elucidation of deactivation phenomena in cobalt catalyst for Fischer-Tropsch synthesis using SSITKA

Author:
Alexandre Carvalho; Vitaly V. Ordomsky; Yuan Luo; Maya Marinova; André R. Muniz; Nilson Romeu Marcilio; Andrei Y. Khodakov
Source:
Journal of catalysis 2016 v.344 pp. 669-679
ISSN:
0021-9517
Subject:
Fischer-Tropsch reaction; active sites; adsorption; carbon; carbon monoxide; catalysts; cobalt; desorption; hydrogen; hydrogenation; kinetics; nanoparticles
Abstract:
... Catalyst deactivation is a major problem in Fischer-Tropsch synthesis. It leads to a decrease in hydrocarbon productivity and loss of active sites in the expensive cobalt catalyst, and thus, undermines the overall efficiency of the technology. In the present paper, the effect of deactivation of silica-supported cobalt catalysts and their reductive rejuvenation on the number of active sites and the ...
DOI:
10.1016/j.jcat.2016.11.001