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 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.

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.

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 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 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 Insights on forming N,O-coordinated Cu single-atom catalysts for electrochemical reduction CO2 to methane

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yanming Cai ◽  
Jiaju Fu ◽  
Yang Zhou ◽  
Yu-Chung Chang ◽  
Qianhao Min ◽  
...  
Keyword(s):  
Energy Barrier ◽  
Active Sites ◽  
Theoretical Calculations ◽  
High Energy ◽  
Single Atom ◽  
Faradaic Efficiency ◽  
High Energy Barrier ◽  
Catalytic Sites ◽  
Electron Reduction ◽  
First Time

AbstractSingle-atom catalysts (SACs) are promising candidates to catalyze electrochemical CO2 reduction (ECR) due to maximized atomic utilization. However, products are usually limited to CO instead of hydrocarbons or oxygenates due to unfavorable high energy barrier for further electron transfer on synthesized single atom catalytic sites. Here we report a novel partial-carbonization strategy to modify the electronic structures of center atoms on SACs for lowering the overall endothermic energy of key intermediates. A carbon-dots-based SAC margined with unique CuN2O2 sites was synthesized for the first time. The introduction of oxygen ligands brings remarkably high Faradaic efficiency (78%) and selectivity (99% of ECR products) for electrochemical converting CO2 to CH4 with current density of 40 mA·cm-2 in aqueous electrolytes, surpassing most reported SACs which stop at two-electron reduction. Theoretical calculations further revealed that the high selectivity and activity on CuN2O2 active sites are due to the proper elevated CH4 and H2 energy barrier and fine-tuned electronic structure of Cu active sites.

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

2021 ◽  
Author(s):  
Guokui Zheng ◽  
Yanle Li ◽  
Xu Qian ◽  
Ge Yao ◽  
Ziqi Tian ◽  
...  
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Single Atom ◽  
Single Atom Alloy

Selective Hydrogenation of Acrolein on a Pd/Ag(111) Single-Atom Alloy Surface

2020 ◽  
Vol 124 (44) ◽  
pp. 24271-24278
Author(s):  
Mark Muir ◽  
David L. Molina ◽  
Arephin Islam ◽  
Mohammed K. Abdel-Rahman ◽  
Michael Trenary
Keyword(s):  
Selective Hydrogenation ◽  
Single Atom ◽  
Alloy Surface ◽  
Single Atom Alloy

scholarly journals Manganese vacancy-confined single-atom Ag in cryptomelane nanorods for efficient Wacker oxidation of styrene derivatives

2021 ◽  
Author(s):  
Hongling Yang ◽  
Xun Zhang ◽  
Yi Yu ◽  
Zheng Chen ◽  
Qinggang Liu ◽  
...  
Keyword(s):  
Molecular Sieve ◽  
Active Sites ◽  
Single Atom ◽  
Wacker Oxidation ◽  
Catalytically Active ◽  
Styrene Derivatives

Single-atom catalysts provide a pathway to elucidate the nature of catalytically active sites. However, keeping them stabilized during operation proves to be challenging. Herein, we employ cryptomelane-type octahedral molecular sieve...

scholarly journals Shifting the scaling relations of single-atom catalysts for facile methane activation by tuning the coordination number

2021 ◽  
Author(s):  
Changhyeok Choi ◽  
Sungho Yoon ◽  
Yousung Jung
Keyword(s):  
Transition State ◽  
Coordination Number ◽  
Active Sites ◽  
Methane Activation ◽  
Single Atom ◽  
Scaling Relations ◽  
Scaling Relationship ◽  
Relationship Of

The scaling relationship of methane activation via a radical-like transition state shifts toward a more reactive region with decreasing coordination number of the active sites.

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