Synergetic role of charge transfer and strain engineering in improving the catalysis of Pd single-atom-thick motifs stabilized on a defect-free MoS2/Ag(Au)(111) heterostructure

2020 ◽  
Vol 8 (33) ◽  
pp. 17238-17247
Author(s):  
Zhixin Su ◽  
Rui Pang ◽  
Xiaoyan Ren ◽  
Shunfang Li
Keyword(s):  
Charge Transfer ◽  
Active Sites ◽  
Catalytic Performance ◽  
Strain Engineering ◽  
Single Atom

Single-atom-thick-PdN magic nanomotifs are demonstrated to be stabilized on defect-free MoS2 overlayer supported on Ag(111) via the synergetic role of charge transfer among the Pd active sites, leading to superior catalytic performance to SAC-Pd1.

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 Effect of the oxygen coordination environment of Ca–Mn oxides on the catalytic performance of Pd supported catalysts for aerobic oxidation of 5-hydroxymethyl-2-furfural

2019 ◽  
Vol 9 (23) ◽  
pp. 6659-6668 ◽  
Author(s):  
Jie Yang ◽  
Haochen Yu ◽  
Yanbing Wang ◽  
Fuyuan Qi ◽  
Haodong Liu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Charge Transfer ◽  
Active Sites ◽  
Supported Catalysts ◽  
Aerobic Oxidation ◽  
Oxygen Adsorption ◽  
Catalytic Performance ◽  
Coordination Environment ◽  
Oxygen Coordination ◽  
Mn Oxides

Pd/CaMn2O4 provides ideal active sites for oxygen adsorption and desorption, resulting in the promoted charge transfer ability and catalytic activity.

scholarly journals Unraveling the coordination structure-performance relationship in Pt1/Fe2O3 single-atom catalyst

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Yujing Ren ◽  
Yan Tang ◽  
Leilei Zhang ◽  
Xiaoyan Liu ◽  
Lin Li ◽  
...  
Keyword(s):  
Coordination Chemistry ◽  
Homogeneous Catalysis ◽  
Catalytic Performance ◽  
Inert Atmosphere ◽  
Single Atom ◽  
Unique Role ◽  
Local Coordination ◽  
Single Atoms ◽  
Heterogeneous And Homogeneous Catalysis

Abstract Heterogeneous single-atom catalyst (SAC) opens a unique entry to establishing structure–performance relationship at the molecular level similar to that in homogeneous catalysis. The challenge lies in manipulating the coordination chemistry of single atoms without changing single-atom dispersion. Here, we develop an efficient synthetic method for SACs by using ethanediamine to chelate Pt cations and then removing the ethanediamine by a rapid thermal treatment (RTT) in inert atmosphere. The coordination chemistry of Pt single atoms on a Fe2O3 support is finely tuned by merely adjusting the RTT temperature. With the decrease in Pt-O coordination number, the oxidation state of Pt decreases, and consequently the hydrogenation activity increases to a record level without loss of chemoselectivity. The tunability of the local coordination chemistry, oxidation states of the metal, and the catalytic performance of single atoms reveals the unique role of SACs as a bridge between heterogeneous and homogeneous catalysis.

scholarly journals A Mini Review of the Preparation and Photocatalytic Properties of Two-Dimensional Materials

2020 ◽  
Vol 8 ◽  
Author(s):  
Shuhua Hao ◽  
Xinpei Zhao ◽  
Qiyang Cheng ◽  
Yupeng Xing ◽  
Wenxuan Ma ◽  
...  
Keyword(s):  
Active Sites ◽  
2D Materials ◽  
Chemical Properties ◽  
Metal Sulfide ◽  
Catalytic Performance ◽  
Theoretical Research ◽  
Single Atom ◽  
Preparation Methods ◽  
Two Dimensional Materials ◽  
Physical And Chemical

The successful preparation and application of graphene shows that it is feasible for the materials with a thickness of a single atom or few atomic layers to exist stably in nature. These materials can exhibit unusual physical and chemical properties due to their special dimension effects. At present, researchers have made great achievements in the preparation, characterization, modification, and theoretical research of 2D materials. Because the structure of 2D materials is often similar, it has a certain degree of qualitative versatility. Besides, 2D materials often carry good catalytic performance on account of their more active sites and adjustable harmonic electronic structure. In this review, taking 2D materials as examples [graphene, boron nitride (h-BN), transition metal sulfide and so on], we review the crystal structure and preparation methods of these materials in recent years, focus on their photocatalyst properties (carbon dioxide reduction and hydrogen production), and discuss their applications and development prospects in the future.

scholarly journals A general strategy for preparing pyrrolic-N4 type single-atom catalysts via pre-located isolated atoms

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Junjie Li ◽  
Ya-fei Jiang ◽  
Qi Wang ◽  
Cong-Qiao Xu ◽  
Duojie Wu ◽  
...  
Keyword(s):  
Active Sites ◽  
Density Functional ◽  
Rational Design ◽  
Catalytic Performance ◽  
Single Atom ◽  
General Strategy ◽  
New Findings ◽  
Synthesis Strategy ◽  
Structure Density ◽  
Application Fields

AbstractSingle-atom catalysts (SACs) have been applied in many fields due to their superior catalytic performance. Because of the unique properties of the single-atom-site, using the single atoms as catalysts to synthesize SACs is promising. In this work, we have successfully achieved Co1 SAC using Pt1 atoms as catalysts. More importantly, this synthesis strategy can be extended to achieve Fe and Ni SACs as well. X-ray absorption spectroscopy (XAS) results demonstrate that the achieved Fe, Co, and Ni SACs are in a M1-pyrrolic N4 (M= Fe, Co, and Ni) structure. Density functional theory (DFT) studies show that the Co(Cp)2 dissociation is enhanced by Pt1 atoms, thus leading to the formation of Co1 atoms instead of nanoparticles. These SACs are also evaluated under hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), and the nature of active sites under HER are unveiled by the operando XAS studies. These new findings extend the application fields of SACs to catalytic fabrication methodology, which is promising for the rational design of advanced SACs.

The promotion effect of π-π interactions in Pd NPs catalysed selective hydrogenation

2021 ◽  
Author(s):  
Miao Guo ◽  
Sanjeevi Jayakumar ◽  
Xiangtao Kong ◽  
Chunzhi Li ◽  
He Li ◽  
...  
Keyword(s):  
Active Sites ◽  
Weak Interactions ◽  
Activation Barrier ◽  
Pd Nanoparticles ◽  
Catalytic Performance ◽  
Supported Metal Catalysts ◽  
Rate Determining Step ◽  
Non Covalent Interactions ◽  
Supported Metal

Abstract The utilization of weak interactions to improve the catalytic performance of supported metal catalysts is an important strategy for catalysts design, but still remains a big challenge. Herein, the weak interactions nearby the Pd nanoparticles (NPs) were finely tuned by using a series of imine-linked covalent organic frameworks (COFs) with different conjugation skeletons. The Pd NPs embedded in pyrene-COF were ca. 3 to 10-fold more active than those in COFs without pyrene in the hydrogenation of aromatic ketones/aldehydes, quinolines and nitrobenzene, though Pd have similar size and surface structure. With acetophenone (AP) hydrogenation as a model reaction, systematic studies imply that the π-π interaction of AP and pyrene rings in the vicinity of Pd NPs could significantly reduce the activation barrier in the rate-determining step. This work highlights the important role of non-covalent interactions beyond the active sites in modulating the catalytic performance of supported metal NPs.

scholarly journals Single-atom catalyst: a rising star for green synthesis of fine chemicals

2018 ◽  
Vol 5 (5) ◽  
pp. 653-672 ◽  
Author(s):  
Leilei Zhang ◽  
Yujing Ren ◽  
Wengang Liu ◽  
Aiqin Wang ◽  
Tao Zhang
Keyword(s):  
Green Synthesis ◽  
Active Sites ◽  
Rational Design ◽  
Heterogeneous Catalysts ◽  
Catalytic Performance ◽  
Research Area ◽  
Single Atom ◽  
Metal Species ◽  
Future Research ◽  
Fine Chemicals

Abstract The green synthesis of fine chemicals calls for a new generation of efficient and robust catalysts. Single-atom catalysts (SACs), in which all metal species are atomically dispersed on a solid support, and which often consist of well-defined mononuclear active sites, are expected to bridge homogeneous and heterogeneous catalysts for liquid-phase organic transformations. This review summarizes major advances in the SAC-catalysed green synthesis of fine chemicals in the past several years, with a focus on the catalytic activity, selectivity and reusability of SACs in various organic reactions. The relationship between catalytic performance and the active site structure is discussed in terms of the valence state, coordination environment and anchoring chemistry of single atoms to the support, in an effort to guide the rational design of SACs in this special area, which has traditionally been dominated by homogeneous catalysis. Finally, the challenges remaining in this research area are discussed and possible future research directions are proposed.

scholarly journals Nanopowder-Supported Ultra-Low Content Co–Rh Bimetallic Catalysts for Hydroformylation of Monoformyltricyclodecenes to Value-Added Fine Chemicals

2018 ◽  
Vol 43 (3-4) ◽  
pp. 254-261
Author(s):  
Chengyang Li ◽  
Libo Zhang ◽  
Yubo Ma ◽  
Tianfu Wang
Keyword(s):  
Reaction Temperature ◽  
Bimetallic Catalysts ◽  
Active Sites ◽  
Value Added ◽  
Catalytic Performance ◽  
Fine Chemicals ◽  
Co Catalysts ◽  
Incipient Wetness ◽  
Incipient Wetness Method

The hydroformylation of monoformyltricyclodecenes (MFTD) to diformyltricyclodecanes (DFTD) was studied systematically. A series of 0.006 wt% Rh–0.006 wt% Co catalysts supported on commercially available nanopowders such as Al2O3, ZnO, TiO2 and CeO2 was prepared by the incipient wetness method and used to catalyse the hydroformylation of MFTD to DFTD. The 0.006 wt% Rh–0.006 wt% Co/ZnO catalyst showed the highest catalytic performance among the catalysts investigated, thus 41.8% DFTD yield with 100% DFTD selectivity could be achieved. This suggested that there may be a key role of the carrier on the catalytic performance in MFTD hydroformylation. Furthermore, the kinetic profiles for MFTD hydroformylation over the 0.006 wt% Rh–0.030 wt% Co/ZnO catalyst have been examined systematically to explore the effect of reaction temperature on the catalytic performance. These results collectively suggested that a particular reaction temperature might benefit MFTD hydroformylation. There may be some agglomeration of the active sites at higher reaction temperatures.

The role of oxophilic Mo species in Pt/MgO catalysts as extremely active sites for enhanced hydrodeoxygenation of dibenzofuran

2020 ◽  
Vol 10 (9) ◽  
pp. 2948-2960
Author(s):  
Jie Zhang ◽  
Chengcheng Zhao ◽  
Chuang Li ◽  
Shenggang Li ◽  
Chi-Wing Tsang ◽  
...  
Keyword(s):  
Surface Density ◽  
Active Sites ◽  
Catalytic Performance

The catalytic performance of the selective hydrodeoxygenation of dibenzofuran can be controlled by the MoOx surface density and varied with the increased MoOx surface density in a volcano-shape manner.

scholarly journals Engineering the Coordination Sphere of Isolated Active Sites to Explore the Intrinsic Activity in Single-Atom Catalysts

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Xin Wu ◽  
Huabin Zhang ◽  
Shouwei Zuo ◽  
Juncai Dong ◽  
Yang Li ◽  
...  
Keyword(s):  
Metallic Nanoparticles ◽  
Active Sites ◽  
Catalytic Performance ◽  
Research Field ◽  
Single Atom ◽  
Intrinsic Activity ◽  
Future Research ◽  
Structure Property ◽  
Coordination Spheres ◽  
Further Development

AbstractReducing the dimensions of metallic nanoparticles to isolated, single atom has attracted considerable attention in heterogeneous catalysis, because it significantly improves atomic utilization and often leads to distinct catalytic performance. Through extensive research, it has been recognized that the local coordination environment of single atoms has an important influence on their electronic structures and catalytic behaviors. In this review, we summarize a series of representative systems of single-atom catalysts, discussing their preparation, characterization, and structure–property relationship, with an emphasis on the correlation between the coordination spheres of isolated reactive centers and their intrinsic catalytic activities. We also share our perspectives on the current challenges and future research promises in the development of single-atom catalysis. With this article, we aim to highlight the possibility of finely tuning the catalytic performances by engineering the coordination spheres of single-atom sites and provide new insights into the further development for this emerging research field.

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