Stepped M@Pt(211) (M = Co, Fe, Mo) single-atom alloys promote deoxygenation of lignin-derived phenolics: mechanism, kinetics and descriptor

2021 ◽  
Author(s):  
Ranran Liu ◽  
Wei An
Keyword(s):  
Catalytic Reaction ◽  
Active Sites ◽  
Single Atom ◽  
Single Atom Alloy ◽  
Single Atom Alloys

The low-coordinated active sites are always intriguing for their unique functionality of promoting specific catalytic reaction. Herein, we employed stepped M@Pt(211) (M = Co, Fe, Mo) single-atom alloy (SAA) to...

scholarly journals Platinum–copper single atom alloy catalysts with high performance towards glycerol hydrogenolysis

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Xi Zhang ◽  
Guoqing Cui ◽  
Haisong Feng ◽  
Lifang Chen ◽  
Hui Wang ◽  
...  
Keyword(s):  
Active Sites ◽  
High Performance ◽  
Reaction Pathway ◽  
Theoretical Calculations ◽  
Experimental Studies ◽  
Value Added ◽  
Catalytic Performance ◽  
Single Atom ◽  
Glycerol Hydrogenolysis ◽  
Single Atom Alloy

AbstractSelective hydrogenolysis of biomass-derived glycerol to propanediol is an important reaction to produce high value-added chemicals but remains a big challenge. Herein we report a PtCu single atom alloy (SAA) catalyst with single Pt atom dispersed on Cu nanoclusters, which exhibits dramatically boosted catalytic performance (yield: 98.8%) towards glycerol hydrogenolysis to 1,2-propanediol. Remarkably, the turnover frequency reaches up to 2.6 × 103 molglycerol·molPtCu–SAA−1·h−1, which is to our knowledge the largest value among reported heterogeneous metal catalysts. Both in situ experimental studies and theoretical calculations verify interface sites of PtCu–SAA serve as intrinsic active sites, in which the single Pt atom facilitates the breakage of central C–H bond whilst the terminal C–O bond undergoes dissociation adsorption on adjacent Cu atom. This interfacial synergistic catalysis based on PtCu–SAA changes the reaction pathway with a decreased activation energy, which can be extended to other noble metal alloy systems.

scholarly journals High-Throughput Screening Single-Atom Alloy for Electroreduction of Dinitrogen to Ammonia

2021 ◽  
Author(s):  
Guokui Zheng ◽  
Ziqi Tian ◽  
Xingwang Zhang ◽  
Liang Chen ◽  
Xu Qian ◽  
...  
Keyword(s):  
High Throughput Screening ◽  
Density Functional ◽  
Ammonia Synthesis ◽  
Density Functional Theory Calculations ◽  
Reduction Reaction ◽  
Single Atom ◽  
Functional Theory ◽  
Metal Doped ◽  
Single Atom Alloy ◽  
Single Atom Alloys

<p></p><p>Exploring electrocatalyst with high activity, selectivity and stability is essential for development of applicable electrocatalytic ammonia synthesis technology. By performing density functional theory calculations, we systematically investigated a series of transition-metal doped Au-based single atom alloys (SAAs) as promising electrocatalysts for nitrogen reduction reaction (NRR). For Au-based electrocatalyst, the first hydrogenation step (*N<sub>2</sub>→*NNH) normally determines the limiting potential of the overall reaction process. Compared with pristine Au(111) surface, introducing single atom can significantly enhance the binding strength of N<sub>2</sub>, leading to decreased energy barrier of the key step, i.e., ΔG(*N<sub>2</sub>→*NNH). According to simulation results, three descriptors were proposed to describe ΔG(*N<sub>2</sub>→*NNH), including ΔG(*NNH), <i>d</i>-band center, and . Eight doped elements (Ti, V, Nb, Ru, Ta, Os, W, and Mo) were initially screened out with limiting potential ranging from -0.75V to -0.30 V. Particularly, Mo- and W-doped systems possess the best activity with limiting potentials of -0.30 V, respectively. Then the intrinsic relationship between structure and the potential performance was further analyzed by using machine-learning. The selectivity, feasibility, stability of these candidates were also evaluated, confirming that SAA containing Mo, Ru ,Ta, and W could be outstanding NRR electrocatalysts. This work not only broadens the understating of SAA application in electrocatalysis, but also devotes to the discovery of novel NRR electrocatalysts.</p><br><p></p>

When More Is Less: Nonmonotonic Trends in Adsorption on Clusters in Alloy Surfaces

2020 ◽  
Author(s):  
Abigale Monasterial ◽  
Calla Hinderks ◽  
Songkun Viriyavaree ◽  
Matthew Montemore
Keyword(s):  
Fermi Energy ◽  
Hydrogen Adsorption ◽  
Single Atom ◽  
Free Standing ◽  
Reactive Metal ◽  
Electronic Density ◽  
Band Center ◽  
Adsorption Energies ◽  
Single Atom Alloy ◽  
Single Atom Alloys

Single-atom alloys can be effective catalysts and have been compared to supported single-atom catalysts. To rationally design single-atom alloys and other surfaces with localized ensembles, it is crucial to understand variations in reactivity when varying the dopant and the ensemble size. Here, we examined hydrogen adsorption on surfaces embedded with localized clusters and discovered general trends. Counterintuitively, increasing the amount of a more reactive metal sometimes makes a surface site less reactive. This behavior is due to the hybridization and splitting of narrow peaks in the electronic density of states of many of these surfaces, making them analogous to free-standing nanoclusters. When a single-atom alloy has a peak just below the Fermi energy, the corresponding two-dopant cluster often has weaker adsorption than the single-atom alloy due to splitting of this peak across the Fermi energy. Further, single-atom alloys have qualitatively different behavior than larger ensembles. Specifically, the adsorption energy is a U-shaped function of the dopant’s group for single atom alloys. Additionally, adsorption energies on single atom alloys correlate more strongly with the dopant’s p-band center than the d-band center.

Palladium–gold single atom alloy catalysts for liquid phase selective hydrogenation of 1-hexyne

2017 ◽  
Vol 7 (19) ◽  
pp. 4276-4284 ◽  
Author(s):  
Jilei Liu ◽  
Junjun Shan ◽  
Felicia R. Lucci ◽  
Sufeng Cao ◽  
E. Charles H. Sykes ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Selective Hydrogenation ◽  
Single Atom ◽  
Mild Conditions ◽  
Alloy Catalysts ◽  
Single Atom Alloy ◽  
Single Atom Alloys

Silica supported and unsupported PdAu single atom alloys (SAAs) were investigated for the selective hydrogenation of 1-hexyne to hexenes under mild conditions.

scholarly journals Efficient and selective carbon–carbon coupling on coke-resistant PdAu single-atom alloys

2019 ◽  
Vol 55 (100) ◽  
pp. 15085-15088 ◽  
Author(s):  
Romain Réocreux ◽  
Matthew Uhlman ◽  
Theodore Thuening ◽  
Paul Kress ◽  
Ryan Hannagan ◽  
...  
Keyword(s):  
Model Catalysts ◽  
Single Atom ◽  
Type C ◽  
Single Atom Alloy ◽  
Single Atom Alloys

We demonstrate that PdAu single-atom alloy model catalysts offer a heterogeneous route to selective Würtz-type C–C coupling.

scholarly journals Directing reaction pathways via in situ control of active site geometries in PdAu single-atom alloy catalysts

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Mengyao Ouyang ◽  
Konstantinos G. Papanikolaou ◽  
Alexey Boubnov ◽  
Adam S. Hoffman ◽  
Georgios Giannakakis ◽  
...  
Keyword(s):  
Active Site ◽  
Active Sites ◽  
Heterogeneous Catalysts ◽  
Bimetallic Catalyst ◽  
Theoretical Calculations ◽  
Atomic Scale ◽  
Single Atom ◽  
In Situ Control ◽  
Single Atom Alloy

AbstractThe atomic scale structure of the active sites in heterogeneous catalysts is central to their reactivity and selectivity. Therefore, understanding active site stability and evolution under different reaction conditions is key to the design of efficient and robust catalysts. Herein we describe theoretical calculations which predict that carbon monoxide can be used to stabilize different active site geometries in bimetallic alloys and then demonstrate experimentally that the same PdAu bimetallic catalyst can be transitioned between a single-atom alloy and a Pd cluster phase. Each state of the catalyst exhibits distinct selectivity for the dehydrogenation of ethanol reaction with the single-atom alloy phase exhibiting high selectivity to acetaldehyde and hydrogen versus a range of products from Pd clusters. First-principles based Monte Carlo calculations explain the origin of this active site ensemble size tuning effect, and this work serves as a demonstration of what should be a general phenomenon that enables in situ control over catalyst selectivity.

scholarly journals Periodic Trends in Adsorption Energies around Single-Atom Alloy Active Sites

2021 ◽  
pp. 10060-10067
Author(s):  
Julia Schumann ◽  
Yutian Bao ◽  
Ryan T. Hannagan ◽  
E. Charles H. Sykes ◽  
Michail Stamatakis ◽  
...  
Keyword(s):  
Active Sites ◽  
Single Atom ◽  
Adsorption Energies ◽  
Single Atom Alloy

scholarly journals High-Throughput Screening Single-Atom Alloy for Electroreduction of Dinitrogen to Ammonia

2021 ◽  
Author(s):  
Guokui Zheng ◽  
Ziqi Tian ◽  
Xingwang Zhang ◽  
Liang Chen ◽  
Xu Qian ◽  
...  
Keyword(s):  
High Throughput Screening ◽  
Density Functional ◽  
Ammonia Synthesis ◽  
Density Functional Theory Calculations ◽  
Reduction Reaction ◽  
Single Atom ◽  
Functional Theory ◽  
Metal Doped ◽  
Single Atom Alloy ◽  
Single Atom Alloys

<p></p><p>Exploring electrocatalyst with high activity, selectivity and stability is essential for development of applicable electrocatalytic ammonia synthesis technology. By performing density functional theory calculations, we systematically investigated a series of transition-metal doped Au-based single atom alloys (SAAs) as promising electrocatalysts for nitrogen reduction reaction (NRR). For Au-based electrocatalyst, the first hydrogenation step (*N<sub>2</sub>→*NNH) normally determines the limiting potential of the overall reaction process. Compared with pristine Au(111) surface, introducing single atom can significantly enhance the binding strength of N<sub>2</sub>, leading to decreased energy barrier of the key step, i.e., ΔG(*N<sub>2</sub>→*NNH). According to simulation results, three descriptors were proposed to describe ΔG(*N<sub>2</sub>→*NNH), including ΔG(*NNH), <i>d</i>-band center, and . Eight doped elements (Ti, V, Nb, Ru, Ta, Os, W, and Mo) were initially screened out with limiting potential ranging from -0.75V to -0.30 V. Particularly, Mo- and W-doped systems possess the best activity with limiting potentials of -0.30 V, respectively. Then the intrinsic relationship between structure and the potential performance was further analyzed by using machine-learning. The selectivity, feasibility, stability of these candidates were also evaluated, confirming that SAA containing Mo, Ru ,Ta, and W could be outstanding NRR electrocatalysts. This work not only broadens the understating of SAA application in electrocatalysis, but also devotes to the discovery of novel NRR electrocatalysts.</p><br><p></p>

scholarly journals When More Is Less: Nonmonotonic Trends in Adsorption on Clusters in Alloy Surfaces

2020 ◽  
Author(s):  
Abigale Monasterial ◽  
Calla Hinderks ◽  
Songkun Viriyavaree ◽  
Matthew Montemore
Keyword(s):  
Fermi Energy ◽  
Hydrogen Adsorption ◽  
Single Atom ◽  
Free Standing ◽  
Reactive Metal ◽  
Electronic Density ◽  
Band Center ◽  
Adsorption Energies ◽  
Single Atom Alloy ◽  
Single Atom Alloys

Single-atom alloys can be effective catalysts and have been compared to supported single-atom catalysts. To rationally design single-atom alloys and other surfaces with localized ensembles, it is crucial to understand variations in reactivity when varying the dopant and the ensemble size. Here, we examined hydrogen adsorption on surfaces embedded with localized clusters and discovered general trends. Counterintuitively, increasing the amount of a more reactive metal sometimes makes a surface site less reactive. This behavior is due to the hybridization and splitting of narrow peaks in the electronic density of states of many of these surfaces, making them analogous to free-standing nanoclusters. When a single-atom alloy has a peak just below the Fermi energy, the corresponding two-dopant cluster often has weaker adsorption than the single-atom alloy due to splitting of this peak across the Fermi energy. Further, single-atom alloys have qualitatively different behavior than larger ensembles. Specifically, the adsorption energy is a U-shaped function of the dopant’s group for single atom alloys. Additionally, adsorption energies on single atom alloys correlate more strongly with the dopant’s p-band center than the d-band center.

scholarly journals Combining STM, RAIRS and TPD to Decipher the Dispersion and Interactions Between Active Sites in RhCu Single‐Atom Alloys

ChemCatChem ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 488-493 ◽  
Author(s):  
Ryan T. Hannagan ◽  
Dipna A. Patel ◽  
Laura A. Cramer ◽  
Alex C. Schilling ◽  
Paul T. P. Ryan ◽  
...  
Keyword(s):  
Active Sites ◽  
Single Atom ◽  
Single Atom Alloys
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