Identification of active sites for CO2 hydrogenation in Fe catalysts by first-principles microkinetic modelling

2020 ◽  
Vol 8 (26) ◽  
pp. 13014-13023 ◽  
Author(s):  
Seung Ju Han ◽  
Sun-Mi Hwang ◽  
Hae-Gu Park ◽  
Chundong Zhang ◽  
Ki-Won Jun ◽  
...  
Keyword(s):  
First Principles ◽  
Active Sites ◽  
Active Phase ◽  
Co2 Hydrogenation ◽  
Fe Catalysts

The active phase of Fe catalysts for RWGS is identified and an efficient promoter is proposed using DFT-microkinetics.

scholarly journals Correction: Identification of active sites for CO2 hydrogenation in Fe catalysts by first-principles microkinetic modelling

2020 ◽  
Vol 8 (35) ◽  
pp. 18385-18385
Author(s):  
Seung Ju Han ◽  
Sun-Mi Hwang ◽  
Hae-Gu Park ◽  
Chundong Zhang ◽  
Ki-Won Jun ◽  
...  
Keyword(s):  
First Principles ◽  
Active Sites ◽  
Co2 Hydrogenation ◽  
Fe Catalysts

Correction for ‘Identification of active sites for CO2 hydrogenation in Fe catalysts by first-principles microkinetic modelling’ by Seung Ju Han et al., J. Mater. Chem. A, 2020, 8, 13014–13023, DOI: 10.1039/D0TA01634A.

scholarly journals Synergistic Effect of Alkali Na and K Promoter on Fe-Co-Cu-Al Catalysts for CO2 Hydrogenation to Light Hydrocarbons

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 735
Author(s):  
Yuhao Zheng ◽  
Chenghua Xu ◽  
Xia Zhang ◽  
Qiong Wu ◽  
Jie Liu
Keyword(s):  
Synergistic Effect ◽  
Active Sites ◽  
Intermediate Formation ◽  
Active Phase ◽  
Dissociative Adsorption ◽  
Co2 Hydrogenation ◽  
Chain Growth ◽  
Co2 Conversion ◽  
Light Hydrocarbons ◽  
Active Centers

Alkali metal K- and/or Na-promoted FeCoCuAl catalysts were synthesized by precipitation and impregnation, and their physicochemical and catalytic performance for CO2 hydrogenation to light hydrocarbons was also investigated in the present work. The results indicate that Na and/or K introduction leads to the formation of active phase metallic Fe and Fe-Co crystals in the order Na < K < K-Na. The simultaneous introduction of Na and K causes a synergistic effect on increasing the basicity and electron-rich property, promoting the formation of active sites Fe@Cu and Fe-Co@Cu with Cu0 as a crystal core. These effects are advantageous to H2 dissociative adsorption and CO2 activation, giving a high CO2 conversion with hydrogenation. Moreover, electron-rich Fe@Cu (110) and Fe-Co@Cu (200) provide active centers for further H2 dissociative adsorption and O-C-Fe intermediate formation after adsorption of CO produced by RWGS. It is beneficial for carbon chain growth in C2+ hydrocarbons, including olefins and alkanes. FeCoCuAl simultaneously modified by K-Na exhibits the highest CO2 conversion and C2+ selectivity of 52.87 mol% and 89.70 mol%, respectively.

What catalysis needs from the electron microscopist

1988 ◽  
Vol 46 ◽  
pp. 694-695
Author(s):  
Alexis T. Bell
Keyword(s):  
Active Sites ◽  
Heterogeneous Catalysts ◽  
Catalyst Deactivation ◽  
Surface Composition ◽  
Internal Surface ◽  
Active Phase ◽  
Atomic Scale ◽  
Metal Catalyst ◽  
Internal Surface Area ◽  
Porous Support

Heterogeneous catalysts, used in industry for the production of fuels and chemicals, are microporous solids characterized by a high internal surface area. The catalyticly active sites may occur at the surface of the bulk solid or of small crystallites deposited on a porous support. An example of the former case would be a zeolite, and of the latter, a supported metal catalyst. Since the activity and selectivity of a catalyst are known to be a function of surface composition and structure, it is highly desirable to characterize catalyst surfaces with atomic scale resolution. Where the active phase is dispersed on a support, it is also important to know the dispersion of the deposited phase, as well as its structural and compositional uniformity, the latter characteristics being particularly important in the case of multicomponent catalysts. Knowledge of the pore size and shape is also important, since these can influence the transport of reactants and products through a catalyst and the dynamics of catalyst deactivation.

scholarly journals Tailoring of Hydrotalcite-Derived Cu-Based Catalysts for CO2 Hydrogenation to Methanol

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1058 ◽  
Author(s):  
Leone Frusteri ◽  
Catia Cannilla ◽  
Serena Todaro ◽  
Francesco Frusteri ◽  
Giuseppe Bonura
Keyword(s):  
Metallic Copper ◽  
Chemical Properties ◽  
Active Phase ◽  
Co2 Hydrogenation ◽  
High Dispersion ◽  
Experimental Conditions ◽  
Typical Structure ◽  
Methanol Production ◽  
Physico Chemical ◽  
Space Time Yield

Ternary CuxZnyAlz catalysts were prepared using the hydrotalcite (HT) method. The influence of the atomic x:y:z ratio on the physico-chemical and catalytic properties under CO2 hydrogenation conditions was probed. The characterization data of the investigated catalysts were obtained by XRF, XRD, BET, TPR, CO2-TPD, N2O chemisorption, SEM, and TEM techniques. In the “dried” catalyst, the typical structure of a hydrotalcite phase was observed. Although the calcination and subsequent reduction treatments determined a clear loss of the hydrotalcite structure, the pristine phase addressed the achievement of peculiar physico-chemical properties, also affecting the catalytic activity. Textural and surface effects induced by the zinc concentration conferred a very interesting catalyst performance, with a methanol space time yield (STY) higher than that of commercial systems operated under the same experimental conditions. The peculiar behavior of the hydrotalcite-like samples was related to a high dispersion of the active phase, with metallic copper sites homogeneously distributed among the oxide species, thereby ensuring a suitable activation of H2 and CO2 reactants for a superior methanol production.

K and Mn doped iron-based CO2 hydrogenation catalysts: Detection of KAlH4 as part of the catalyst's active phase

2010 ◽  
Vol 373 (1-2) ◽  
pp. 112-121 ◽  
Author(s):  
Robert W. Dorner ◽  
Dennis R. Hardy ◽  
Frederick W. Williams ◽  
Heather D. Willauer
Keyword(s):  
Active Phase ◽  
Co2 Hydrogenation ◽  
Hydrogenation Catalysts ◽  
Iron Based ◽  
Mn Doped

CO2 hydrogenation into CH4 over Ni–Fe catalysts

2018 ◽  
Vol 11 (03) ◽  
pp. 1850057 ◽  
Author(s):  
Reza Meshkini Far ◽  
Olena V. Ischenko ◽  
Alla G. Dyachenko ◽  
Oleksandr Bieda ◽  
Snezhana V. Gaidai ◽  
...  
Keyword(s):  
Low Temperature ◽  
Synergistic Effect ◽  
Atmospheric Pressure ◽  
High Efficiency ◽  
Co2 Hydrogenation ◽  
Hydrogenation Catalysts ◽  
Fe Catalysts ◽  
First Time ◽  
Supported Ni ◽  
Hydrogenation Of Co

Here, we report, for the first time, on the catalytic hydrogenation of CO2 to methane at atmospheric pressure. For the preparation of hydrogenation catalysts based on Ni and Fe metals, a convenient method is developed. According to this method, low-temperature reduction of the co-precipitated Ni and Fe oxides with hydrogen gives the effective and selective bimetallic Ni[Formula: see text]Fe[Formula: see text], Ni[Formula: see text]Fe[Formula: see text] and Ni[Formula: see text]Fe[Formula: see text] catalysts. At the temperature range of 300–400[Formula: see text]C, they exhibit a high efficiency of CH4 production with respect to monometallic Ni and Fe catalysts. The results imply a synergistic effect between Ni and Fe which caused the superior activity of the Ni[Formula: see text]Fe[Formula: see text] catalyst conversing [Formula: see text]% of CO2 into CH4 at 350[Formula: see text]C. To adapt the Ni–Fe catalysts in the industry, the effect of two different carriers on the efficiency of the alumina-supported Ni[Formula: see text]Fe[Formula: see text] catalyst was investigated. It is found that the Ni[Formula: see text]Fe[Formula: see text]/[Formula: see text]-Al2O3 catalyst effectively conversed CO2 giving 100% methane yield already at 275[Formula: see text]C.

Zn and Na promoted Fe catalysts for sustainable production of high-valued olefins by CO2 hydrogenation

Fuel ◽  
2022 ◽  
Vol 309 ◽  
pp. 122105
Author(s):  
Zhiqiang Zhang ◽  
Gongxun Huang ◽  
Xinglei Tang ◽  
Haoren Yin ◽  
Jincan Kang ◽  
...  
Keyword(s):  
Co2 Hydrogenation ◽  
Sustainable Production ◽  
Fe Catalysts

The Selective Oxidation of Hydrocarbons on Isolated Iron Active Sites under Ambient Conditions

2019 ◽  
Vol 41 (6) ◽  
pp. 946-946
Author(s):  
Zhengliang Qi Zhengliang Qi ◽  
Junmei Liu Junmei Liu ◽  
Wanwan Guo and Jun Huang Wanwan Guo and Jun Huang
Keyword(s):  
Ionic Liquid ◽  
Activated Carbon ◽  
Carbon Material ◽  
Active Sites ◽  
High Selectivity ◽  
Good Activity ◽  
Ambient Conditions ◽  
Oxidation Of Hydrocarbons ◽  
Fe Catalysts ◽  
Iron Active Sites

The N-doped carbon material supported Fe catalysts were developed for the oxidation of C-H bond of hydrocarbons to ketones and alcohols. The supported Fe catalysts were prepared by pyrolysis of [CMIM]3Fe(CN)6 ionic liquid in activated carbon. And the Fe(Ⅲ)@CN-600 showed good activity and high selectivity for the oxidation of alfa C-H bond of alkylbenzenes. The isolated Fe(Ⅲ) iron active sites should be responsible for the high activity and selectivity for the oxidation of hydrocarbons to ketones. Several ketones were obtained in good to excellent yields. Moreover, cyclohexanone can also be obtained through the oxidation of cyclohexane.

scholarly journals Influence of Bio-Oil Phospholipid on the Hydrodeoxygenation Activity of NiMoS/Al2O3 Catalyst

Catalysts ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 418 ◽  
Author(s):  
Muhammad Abdus Salam ◽  
Derek Creaser ◽  
Prakhar Arora ◽  
Stefanie Tamm ◽  
Eva Lind Grennfelt ◽  
...  
Keyword(s):  
Active Sites ◽  
Batch Reactor ◽  
Active Phase ◽  
Aluminum Phosphate ◽  
Spent Catalyst ◽  
Bio Oil ◽  
Pore Blockage ◽  
Sulfided Catalyst ◽  
High Degree

Hydrodeoxygenation (HDO) activity of a typical hydrotreating catalyst, sulfided NiMo/γ-Al2O3 for deoxygenation of a fatty acid has been explored in a batch reactor at 54 bar and 320 °C in the presence of contaminants, like phospholipids, which are known to be present in renewable feeds. Oleic acid was used for the investigation. Freshly sulfided catalyst showed a high degree of deoxygenation activity; products were predominantly composed of alkanes (C17 and C18). Experiments with a major phospholipid showed that activity for C17 was greatly reduced while activity to C18 was not altered significantly in the studied conditions. Characterization of the spent catalyst revealed the formation of aluminum phosphate (AlPO4), which affects the active phase dispersion, blocks the active sites, and causes pore blockage. In addition, choline, formed from the decomposition of phospholipid, partially contributes to the observed deactivation. Furthermore, a direct correlation was observed in the accumulation of coke on the catalyst and the amount of phospholipid introduced in the feed. We therefore propose that the reason for the increased deactivation is due to the dual effects of an irreversible change in phase to aluminum phosphate and the formation of choline.

scholarly journals Mononuclear Fe in N-doped carbon: computational elucidation of active sites for electrochemical oxygen reduction and oxygen evolution reactions

2020 ◽  
Vol 10 (4) ◽  
pp. 1006-1014 ◽  
Author(s):  
Rui Shang ◽  
Stephan N. Steinmann ◽  
Bo-Qing Xu ◽  
Philippe Sautet
Keyword(s):  
Oxygen Reduction ◽  
Oxygen Evolution ◽  
Electrostatic Potential ◽  
First Principles ◽  
Active Sites ◽  
High Potential ◽  
Major Influence ◽  
Co Doped ◽  
Electrochemical Oxygen

First principles simulations show that in Fe and N co-doped carbon, Fe coordination controls the activity for oxygen reduction and oxygen evolution reactions, and that including the electrostatic potential has a major influence at high potential.

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