Reaction mechanism for methanol oxidation on Au(111): A density functional theory study

Liu, Shuping; Jin, Peng; Zhang, Donghui; Hao, Ce; Yang, Xueming

doi:10.1016/j.apsusc.2012.11.026

Cited by 29 publications

(29 citation statements)

References 53 publications

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“…This step is slightly exothermic on Au(111) (Δ E = −0.35 eV) and Au(100) (Δ E = −0.17 eV) and near‐thermo neutral on Au(211) (Δ E = −0.08 eV). E A for this step is relatively invariant of the model surface, with values of 0.80 (0.65 eV), 0.84, and 0.85 eV on Au(111), Au(100), and Au(211), respectively

{COOH}^{*} +^{*} \to {CO}_{2}^{*} + {normalH}^{*}

…”

Section: Resultsmentioning

confidence: 99%

Formic acid decomposition on Au catalysts: DFT, microkinetic modeling, and reaction kinetics experiments

et al. 2014

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A combined theoretical and experimental approach is presented that uses a comprehensive mean‐field microkinetic model, reaction kinetics experiments, and scanning transmission electron microscopy imaging to unravel the reaction mechanism and provide insights into the nature of active sites for formic acid (HCOOH) decomposition on Au/SiC catalysts. All input parameters for the microkinetic model are derived from periodic, self‐consistent, generalized gradient approximation (GGA‐PW91) density functional theory calculations on the Au(111), Au(100), and Au(211) surfaces and are subsequently adjusted to describe the experimental HCOOH decomposition rate and selectivity data. It is shown that the HCOOH decomposition follows the formate (HCOO) mediated path, with 100% selectivity toward the dehydrogenation products (CO2 + H2) under all reaction conditions. An analysis of the kinetic parameters suggests that an Au surface in which the coordination number of surface Au atoms is ≤4 may provide a better model for the active site of HCOOH decomposition on these specific supported Au catalysts. © 2014 American Institute of Chemical Engineers AIChE J, 60: 1303–1319, 2014

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{COOH}^{*} +^{*} \to {CO}_{2}^{*} + {normalH}^{*}

…”

Section: Resultsmentioning

confidence: 99%

Formic acid decomposition on Au catalysts: DFT, microkinetic modeling, and reaction kinetics experiments

et al. 2014

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“…Next, we used an empirical Lennard-Jones 6-12 potential (''L-J''), with parameters taken from the UFF force field. 38 The UFF van der Waals interaction underestimates the measured 30 and calculated [39][40][41] binding energy of formaldehyde on Au(111) by more than an order of magnitude, so we scale the potential by a factor of 41 in order to bring the optimized binding energy into agreement with the measured value (0.31 eV). 30 The trajectories were calculated at normal incidence angle and random incidence orientation, over a range of incidence kinetic energies (E i = 0.33-1.2 eV).…”

Section: Paper Pccpmentioning

confidence: 99%

An axis-specific rotational rainbow in the direct scatter of formaldehyde from Au(111) and its influence on trapping probability

Park

Krüger

Meyer

et al. 2017

Phys. Chem. Chem. Phys.

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The conversion of translational to rotational motion often plays a major role in the trapping of small molecules at surfaces, a crucial first step for a wide variety chemical processes that occur at gas-surface interfaces. However, to date most quantum-state resolved surface scattering experiments have been performed on diatomic molecules, and little detailed information is available about how the structure of nonlinear polyatomic molecules influences the mechanisms for energy exchange with surfaces. In the current work, we employ a new rotationally resolved 1 + 1' resonance-enhanced multiphoton ionization (REMPI) scheme to measure the rotational distribution in formaldehyde molecules directly scattered from the Au(111) surface at incidence kinetic energies in the range 0.3-1.2 eV. The results indicate a pronounced propensity to excite a-axis rotation (twirling) rather than b- or c-axis rotation (tumbling or cartwheeling), and are consistent with a rotational rainbow scattering model. Classical trajectory calculations suggest that the effect arises-to zeroth order-from the three-dimensional shape of the molecule (steric effects). Analysis suggests that the high degree of rotational excitation has a substantial influence on the trapping probability of formaldehyde at incidence translational energies above 0.5 eV.

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“…Firstly, increasing the barrier of oxygen dissociative adsorption on metal surfaces can be effectively improving the overall TOF, which may be achieved by using other metal substrates. Inert metals can be potential candidates as the metal substrates, such as Ag and Au, which show a higher activation energy for oxygen dissociation [59][60][61] and have a similar methanol binding strength 62 , which is also applicable in other oxidation reaction on oxidebased catalysts. [63][64] It is clear that the O* binding strength at interface sites should be at least stronger than that at the sites of mono-phase constituent; otherwise, the interfacial O* will likely diffuse to the metal surface.…”

Section: Kinetic Study Of Overall Catalytic Cyclementioning

confidence: 99%

Understanding the Dual Active Sites of the FeO/Pt(111) Interface and Reaction Kinetics: Density Functional Theory Study on Methanol Oxidation to Formaldehyde

Chen¹,

Mao²,

Chen

et al. 2017

ACS Catal.

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Identifying the active sites and reaction kinetics for a catalytic reaction can provide significant insight to the catalytic systems. By conducting DFT calculations, the catalytic activity of FeO/Pt(111) interfacial sites, which is an important class of catalyst with excellent activity, for methanol partial oxidation is carefully examined and compared. The O-H cleavage barrier of methanol is significantly diminished to below 0.1 eV with the aid of interfacial oxygen, which is much lower than that on the Pt(111) surface (> 0.8 eV). The CH3O* intermediate can further undergo a C-H bond breaking process to produce formaldehyde via a low barrier (~ 0.2 eV) at the interfacial Pt sites. Assisted by interfacial Pt-O ensemble, the O-H and C-H bond cleavage are greatly facilitated, suggesting that the FeO/Pt bi-phase system could effectively combine the advantages of two individual phases. To investigate the rate determining steps, a multi-site 2 / 32 micro-kinetic model is applied at FeO/Pt interface. The results show that the overall rate can be significantly improved by lower the activation energy of interfacial oxygen removal steps. Interestingly, the turnover frequency (TOF) can also be enlarged when increasing the barriers of O2 dissociative adsorption on the Pt flat surface, which is a special feature in multi-phase systems comparing with the mono-phase one. The active site and micro-kinetic studies in our work can provide insights into the development of metal/oxide catalysts for the partial oxidation of methanol or other primary alcohols.

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Reaction mechanism for methanol oxidation on Au(111): A density functional theory study

Cited by 29 publications

References 53 publications

Formic acid decomposition on Au catalysts: DFT, microkinetic modeling, and reaction kinetics experiments

Formic acid decomposition on Au catalysts: DFT, microkinetic modeling, and reaction kinetics experiments

An axis-specific rotational rainbow in the direct scatter of formaldehyde from Au(111) and its influence on trapping probability

Understanding the Dual Active Sites of the FeO/Pt(111) Interface and Reaction Kinetics: Density Functional Theory Study on Methanol Oxidation to Formaldehyde

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