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.

The impacts of nanotechnology on catalysis by precious metal nanoparticles

2012 ◽  
Vol 1 (1) ◽  
pp. 31-56 ◽  
Author(s):  
Rongchao Jin
Keyword(s):  
Metal Nanoparticles ◽  
Precious Metal ◽  
Metallic Nanoparticles ◽  
Active Sites ◽  
Active Surface ◽  
Catalytic Performance ◽  
Solution Phase ◽  
Future Research ◽  
Metal Support ◽  
Effect Of Surface

AbstractThis review article focuses on the impacts of recent advances in solution phase precious metal nanoparticles on heterogeneous catalysis. Conventional nanometal catalysts suffer from size polydispersity. The advent of nanotechnology has significantly advanced the techniques for preparing uniform nanoparticles, especially in solution phase synthesis of precious metal nanoparticles with excellent control over size, shape, composition and morphology, which have opened up new opportunities for catalysis. This review summarizes some recent catalytic research by using well-defined nanoparticles, including shape-controlled nanoparticles, high index-faceted polyhedral nanocrystals, nanostructures of different morphology (e.g., core-shell, hollow, etc.), bi- and multi-metallic nanoparticles, as well as atomically precise nanoclusters. Such well-defined nanocatalysts provide many exciting opportunities, such as identifying the types of active surface atoms (e.g., corner and edge atoms) in catalysis, the effect of surface facets on catalytic performance, and obtaining insight into the effects of size-induced electron energy quantization in ultra-small metal nanoparticles on catalysis. With well-defined metal nanocatalysts, many fundamentally important issues are expected to be understood much deeper in future research, such as the nature of the catalytic active sites, the metal-support interactions, the effect of surface atom arrangement, and the atomic origins of the structure-activity and the structure-selectivity relationships.

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 Microenvironment modulation of single-atom catalysts and their roles in electrochemical energy conversion

2020 ◽  
Vol 6 (39) ◽  
pp. eabb6833 ◽  
Author(s):  
Xuning Li ◽  
Linghui Liu ◽  
Xinyi Ren ◽  
Jiajian Gao ◽  
Yanqiang Huang ◽  
...  
Keyword(s):  
Energy Conversion ◽  
Active Sites ◽  
Water Electrolysis ◽  
Research Field ◽  
Single Atom ◽  
Metal Atoms ◽  
Electrochemical Energy Conversion ◽  
Further Development ◽  
Covalent Interactions ◽  
Electrochemical Energy

Single-atom catalysts (SACs) have become the most attractive frontier research field in heterogeneous catalysis. Since the atomically dispersed metal atoms are commonly stabilized by ionic/covalent interactions with neighboring atoms, the geometric and electronic structures of SACs depend greatly on their microenvironment, which, in turn, determine the performances in catalytic processes. In this review, we will focus on the recently developed strategies of SAC synthesis, with attention on the microenvironment modulation of single-atom active sites of SACs. Furthermore, experimental and computational advances in understanding such microenvironment in association to the catalytic activity and mechanisms are summarized and exemplified in the electrochemical applications, including the water electrolysis and O2/CO2/N2 reduction reactions. Last, by highlighting the prospects and challenges for microenvironment engineering of SACs, we wish to shed some light on the further development of SACs for electrochemical energy conversion.

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 Au-Pd Bimetallic Nanocatalysts Incorporated into Carbon Nanotubes (CNTs) for Selective Oxidation of Alkenes and Alcohol

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1380
Author(s):  
Hamed M. Alshammari ◽  
Abdullah S. Alshammari ◽  
Jamal R. Humaidi ◽  
Salma A. Alzahrani ◽  
Mosaed S. Alhumaimess ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Benzyl Alcohol ◽  
Metallic Nanoparticles ◽  
Active Sites ◽  
Bimetallic Nanoparticles ◽  
Catalytic Performance ◽  
Transmission Electron ◽  
Nanocomposite Catalysts ◽  
Bimetallic Nanocatalysts

Although supported bimetallic nanoparticles (Au-Pd NPs) demonstrate outstanding efficiency, challenges appear for carbon supported small and stable bimetallic nanoparticles used in liquid-phase reactions. In this work, Au-Pd NPs were supported on two types of carbon nanotubes: CNTs decorated covalently with carboxylic acid groups (O-CNTs) and non-covalently with the conductive poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) polymer (P-CNTs). The Au-Pd NPs were prepared using the sol immobilization approach on the functionalized CNTs, and the effect of the utilized functionalization method on the properties of the immobilized metallic nanoparticles and the performance of the nanocomposite catalysts was investigated. The fabricated nanocomposites were characterized using Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, High-resolution transmission electron microscopy (HRTEM) and scanning electron microscopy (SEM). The catalytic performance of Au-Pd/O-CNTs and Au-Pd/P-CNTs was exploited for the oxidation of both cyclooctene and benzyl alcohol. Oxidation and polymer decoration directly led to an enhancement in the performance of CNTs catalysts. The nanocomposite catalyst with oxidized CNTs (Au-Pd/O-CNTs) was also found to be much more efficient and robust than that with polymer decorated CNTs (Au-Pd/P-CNTs). The enhancement in the oxidation of both cyclooctene and benzyl alcohol on Au-Pd/O-CNTs is attributed to the well-dispersed and smaller Au-Pd NPs as active sites on the surface of O-CNTs as compared to the P-CNTs surface.

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 Bridging Adsorption Analytics and Catalytic Kinetics for Metal-Exchanged Zeolites

2020 ◽  
Author(s):  
Pengfei Xie ◽  
Tiancheng Pu ◽  
Gregory Aranovich ◽  
Jiawei Guo ◽  
Marc Donohue ◽  
...  
Keyword(s):  
Low Temperature ◽  
Active Sites ◽  
Molecular Spectroscopy ◽  
Catalytic Performance ◽  
Quantitative Information ◽  
Adsorption Properties ◽  
Structure Property ◽  
Atomic Structures ◽  
Structure Property Relationships ◽  
High Temperature Reaction

Abstract Metal-exchanged zeolites have been widely used in industrial catalysis and separation, but fundamental understanding of their structure-property relationships has remained challenging, largely due to the lack of quantitative information concerning the atomic structures and reaction-relevant adsorption properties of the embedded metal active sites. We report on the use of low-temperature chemisorption to titrate Cu-exchanged ZSM5. Quantitative descriptors of the atomic structures and adsorption properties of Cu-ZSM5 are established by combining atomistic simulation, DFT calculations, operando molecular spectroscopy, chemisorption and titration measurements. These descriptors are then applied to interpret the catalytic performance of Cu-ZSM5 for NO decomposition. Linear correlations are established to bridge the low-temperature adsorption analytics and high-temperature reaction kinetics, which are demonstrated to be generally applicable for understanding the structure-property relationships of metal exchanged zeolites and foregrounded for guiding the development of advanced catalytic materials.

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.

scholarly journals Active Sites in Heterogeneous Catalytic Reaction on Metal and Metal Oxide: Theory and Practice

Catalysts ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 478 ◽  
Author(s):  
Yanbo Pan ◽  
Xiaochen Shen ◽  
Libo Yao ◽  
Abdulaziz Bentalib ◽  
Zhenmeng Peng
Keyword(s):  
Metal Oxide ◽  
Active Sites ◽  
Research Direction ◽  
Short Review ◽  
Research Field ◽  
Theory And Practice ◽  
Future Research ◽  
Heterogeneous Catalytic ◽  
The Past ◽  
Catalysis Process

Active sites play an essential role in heterogeneous catalysis and largely determine the reaction properties. Yet identification and study of the active sites remain challenging owing to their dynamic behaviors during catalysis process and issues with current characterization techniques. This article provides a short review of research progresses in active sites of metal and metal oxide catalysts, which covers the past achievements, current research status, and perspectives in this research field. In particular, the concepts and theories of active sites are introduced. Major experimental and computational approaches that are used in active site study are summarized, with their applications and limitations being discussed. An outlook of future research direction in both experimental and computational catalysis research is provided.

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.

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