Water-promoted interfacial pathways in methane oxidation to methanol on a CeO2-Cu2O catalyst

Science ◽  
2020 ◽  
Vol 368 (6490) ◽  
pp. 513-517 ◽  
Author(s):  
Zongyuan Liu ◽  
Erwei Huang ◽  
Ivan Orozco ◽  
Wenjie Liao ◽  
Robert M. Palomino ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Photoelectron Spectroscopy ◽  
Density Functional ◽  
Kinetic Monte Carlo ◽  
Bond Cleavage ◽  
Ambient Pressure ◽  
Density Functional Theory Calculations ◽  
Methanol Production ◽  
Methoxy Groups

Highly selective oxidation of methane to methanol has long been challenging in catalysis. Here, we reveal key steps for the pro­motion of this reaction by water when tuning the selectivity of a well-defined CeO2/Cu2O/Cu(111) catalyst from carbon monoxide and carbon dioxide to methanol under a reaction environment with methane, oxygen, and water. Ambient-pressure x-ray photoelectron spectroscopy showed that water added to methane and oxygen led to surface methoxy groups and accelerated methanol production. These results were consistent with density functional theory calculations and kinetic Monte Carlo simulations, which showed that water preferentially dissociates over the active cerium ions at the CeO2–Cu2O/Cu(111) interface. The adsorbed hydroxyl species blocked O-O bond cleavage that would dehydrogenate methoxy groups to carbon monoxide and carbon dioxide, and it directly converted this species to methanol, while oxygen reoxidized the reduced surface. Water adsorption also displaced the produced methanol into the gas phase.

Influence of intramolecular interactions on carbon dioxide gas adsorption capacity in Mesoporous Imine polymers

2018 ◽  
Author(s):  
Jaya Prakash Madda ◽  
Pilli Govindaiah ◽  
Sushant Kumar Jena ◽  
Sabbhavat Krishna ◽  
Rupak Kishor
Keyword(s):  
Carbon Dioxide ◽  
Adsorption Capacity ◽  
Density Functional ◽  
Gas Adsorption ◽  
Ambient Pressure ◽  
Condensation Reaction ◽  
Intramolecular Interactions ◽  
Carbon Dioxide Adsorption ◽  
Nitrogen Gas ◽  
Adsorption Characteristic

<p>Covalent organic Imine polymers with intrinsic meso-porosity were synthesized by condensation reaction between 4,4-diamino diphenyl methane and (para/meta/ortho)-phthaladehyde. Even though these polymers were synthesized from precursors of bis-bis covalent link mode, the bulk materials were micrometer size particles with intrinsic mesoporous enables nitrogen as well as carbon dioxide adsorption in the void spaces. These polymers were showed stability up to 260<sup>o</sup> centigrade. Nitrogen gas adsorption capacity up to 250 cc/g in the ambient pressure was observed with type III adsorption characteristic nature. Carbon dioxide adsorption experiments reveal the possible terminal amine functional group to carbamate with CO<sub>2</sub> gas molecule to the polymers. One of the imine polymers, COP-3 showed more carbon dioxide sorption capacity and isosteric heat of adsorption (Q<sub>st</sub>) than COP-1 and COP-2 at 273 K even though COP-3 had lower porosity for nitrogen gas than COP-1 and COP-2. We explained the trends in gas adsorption capacities and Qst values as a consequence of the intra molecular interactions confirmed by Density Functional Theory computational experiments on small molecular fragments.</p>

scholarly journals Selective capture of carbon dioxide from hydrocarbons using a metal-organic framework

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Omid T. Qazvini ◽  
Ravichandar Babarao ◽  
Shane G. Telfer
Keyword(s):  
Carbon Dioxide ◽  
Density Functional ◽  
Metal Organic Framework ◽  
Density Functional Theory Calculations ◽  
Time Lags ◽  
X Ray Crystallography ◽  
Metal Organic ◽  
Adsorption Of Co ◽  
Short Time ◽  
Organic Framework

AbstractEfficient and sustainable methods for carbon dioxide capture are highly sought after. Mature technologies involve chemical reactions that absorb CO2, but they have many drawbacks. Energy-efficient alternatives may be realised by porous physisorbents with void spaces that are complementary in size and electrostatic potential to molecular CO2. Here, we present a robust, recyclable and inexpensive adsorbent termed MUF-16. This metal-organic framework captures CO2 with a high affinity in its one-dimensional channels, as determined by adsorption isotherms, X-ray crystallography and density-functional theory calculations. Its low affinity for other competing gases delivers high selectivity for the adsorption of CO2 over methane, acetylene, ethylene, ethane, propylene and propane. For equimolar mixtures of CO2/CH4 and CO2/C2H2, the selectivity is 6690 and 510, respectively. Breakthrough gas separations under dynamic conditions benefit from short time lags in the elution of the weakly-adsorbed component to deliver high-purity hydrocarbon products, including pure methane and acetylene.

Carbon dioxide adsorption and activation on gallium phosphide surface monitored by ambient pressure x-ray photoelectron spectroscopy

2021 ◽  
Vol 54 (23) ◽  
pp. 234002
Author(s):  
Yifan Ye ◽  
Hongyang Su ◽  
Kyung-Jae Lee ◽  
David Larson ◽  
Carlos Valero-Vidal ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Photoelectron Spectroscopy ◽  
Gallium Phosphide ◽  
Ambient Pressure ◽  
Carbon Dioxide Adsorption ◽  
X Ray

First-Principles DFT Insights into the Mechanisms of CO2 Reduction to CO on Fe (100)-Ni Bimetals

2021 ◽  
Author(s):  
Caroline Kwawu ◽  
Albert Aniagyei ◽  
Destiny Konadu ◽  
Elliot Menkah ◽  
Richard Tia
Keyword(s):  
Carbon Monoxide ◽  
Binding Site ◽  
Active Sites ◽  
Density Functional ◽  
Co2 Reduction ◽  
Density Functional Theory Calculations ◽  
Hydrocarbon Fuel ◽  
Generalized Gradient ◽  
Efficient Catalyst ◽  
Stepped Surface

Abstract Iron and nickel are known active sites in the enzyme carbon monoxide dehydrogenases (CODH) which catalyzes CO2 to CO reversibly. The presence of nickel impurities in the earth abundant iron surface could provide a more efficient catalyst for CO2 degradation into CO, which is a feedstock for hydrocarbon fuel production. In the present study, we have employed spin-polarized dispersion-corrected density functional theory calculations within the generalized gradient approximation to elucidate the active sites on Fe (100)-Ni bimetals. We sort to ascertain the mechanism of CO2 dissociation to carbon monoxide on Ni deposited and alloyed surfaces at 0.25, 0.50 and 1 monolayer (ML) impurity concentrations. CO2 and (CO + O) bind exothermically i.e., -0.87 eV and − 1.51 eV respectively to the bare Fe (100) surface with a decomposition barrier of 0.53 eV. The presence of nickel generally lowers the amount of charge transferred to CO2 moiety. Generally, the binding strengths of CO2 were reduced on the modified surfaces and the extent of its activation was lowered. The barriers for CO2 dissociation increased mainly upon introduction of Ni impurities which is undesired. However, the 0.5 ML deposited (FeNi0.5(A)) surface is promising for CO2 decomposition, providing a lower energy barrier (of 0.32 eV) than the pristine Fe (100) surface. This active 1-dimensional defective FeNi0.5(A) surface provides a stepped surface and Ni-Ni bridge binding site for CO2 on Fe (100). Ni-Ni bridge site on Fe (100) is more effective for both CO2 binding or sequestration and dissociation compared to the stepped surface providing the Fe-Ni bridge binding site.

scholarly journals High-Pressure Structural Behavior and Equation of State of Kagome Staircase Compound, Ni3V2O8

Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 910
Author(s):  
Daniel Diaz-Anichtchenko ◽  
Robin Turnbull ◽  
Enrico Bandiello ◽  
Simone Anzellini ◽  
Daniel Errandonea
Keyword(s):  
High Pressure ◽  
Equation Of State ◽  
Density Functional ◽  
Room Temperature ◽  
Ambient Pressure ◽  
Density Functional Theory Calculations ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
A Chain

We report on high-pressure synchrotron X-ray diffraction measurements on Ni3V2O8 at room-temperature up to 23 GPa. According to this study, the ambient-pressure orthorhombic structure remains stable up to the highest pressure reached in the experiments. We have also obtained the pressure dependence of the unit-cell parameters, which reveals an anisotropic compression behavior. In addition, a room-temperature pressure–volume third-order Birch–Murnaghan equation of state has been obtained with parameters: V0 = 555.7(2) Å3, K0 = 139(3) GPa, and K0′ = 4.4(3). According to this result, Ni3V2O8 is the least compressible kagome-type vanadate. The changes of the crystal structure under compression have been related to the presence of a chain of edge-sharing NiO6 octahedral units forming kagome staircases interconnected by VO4 rigid tetrahedral units. The reported results are discussed in comparison with high-pressure X-ray diffraction results from isostructural Zn3V2O8 and density-functional theory calculations on several isostructural vanadates.

The interplay between structural perfectness and CO oxidation catalysis on aluminum, phosphorous and silicon complexes of corroles

2019 ◽  
Vol 21 (14) ◽  
pp. 7661-7674 ◽  
Author(s):  
Afshan Mohajeri ◽  
Nasim Hassani
Keyword(s):  
Density Functional Theory ◽  
Carbon Monoxide ◽  
Co Oxidation ◽  
Catalytic Oxidation ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Oxidation Catalysis ◽  
Functional Theory ◽  
Oxidation Of Carbon Monoxide

Catalytic oxidation of carbon monoxide on perfect and defective structures of corrole complexes with aluminum, phosphorous and silicon have been investigated by performing density functional theory calculations.

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