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.

Noble metal enhanced photocatalytic activity of heterostructured TiO2 spheres with tunable interiors and shells

2020 ◽  
Vol 13 (08) ◽  
pp. 2050039
Author(s):  
Bo Qiu ◽  
Xin Xiao ◽  
Min Zhang ◽  
Yue Mao ◽  
Xiaoheng Liu
Keyword(s):  
Metal Nanoparticles ◽  
Noble Metal ◽  
Precious Metal ◽  
Active Sites ◽  
Inner Core ◽  
Catalytic Performance ◽  
Noble Metal Nanoparticles ◽  
Oxide Support ◽  
Metal Support Interaction ◽  
Metal Support

Heterostructured TiO2 spheres with tunable interiors and shells were prepared by self-template technology. This structure is composed of a hollow shell and an inner core which can enhance light scattering in the hollow space and provide a large surface to generate sufficient active sites. Besides, the nanosheets grown on the shell layer not only increased their specific surface area, but also exposed more surface-active sites. The performance of photocatalysts was estimated by the RhB decolorization, and experimental results show that the photoactivity can be greatly improved by depositing noble metal nanoparticles. It improves the efficiency of charge utilization and enhances the overall catalytic performance from the three stages of charge carrier generation, separation and surface reaction. The strong metal–support interaction (SMSI) between the noble metal nanoparticles and the oxide support has been proven to inhibit the supported precious metal, one strategy for nanoparticle aggregation and growth. On the one hand, the nanoshells isolate the precious metal nanoparticles from each other, preventing the aggregation of metal nanoparticles.

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.

Influence of Pt Size and CeO2 Morphology at the Pt-CeO2 Interface in CO Oxidation

2021 ◽  
Author(s):  
Sinmyung Yoon ◽  
Hyunwoo Ha ◽  
Jihun Kim ◽  
Eonu Nam ◽  
Mi Yoo ◽  
...  
Keyword(s):  
Co Oxidation ◽  
Metal Nanoparticles ◽  
Rational Design ◽  
Catalytic Performance ◽  
Electronic Interactions ◽  
Oxide Supports ◽  
Metal Support ◽  
Metal Support Interactions

Understanding the inherent catalytic nature of the interface between metal nanoparticles (NPs) and oxide supports enables the rational design of metal-support interactions for high catalytic performance. Electronic interactions at the...

Microfluidic Synthesis and Electrochemical Performance of Ternary Metals Nanoalloy: FePtSn

2018 ◽  
Vol 913 ◽  
pp. 831-837
Author(s):  
Ju Gang Ma ◽  
Jun Mei Wang ◽  
Shuai Li ◽  
Yu Jun Song
Keyword(s):  
Electrochemical Performance ◽  
Active Sites ◽  
Annealing Treatment ◽  
Active Surface ◽  
Catalytic Performance ◽  
Synthesis Process ◽  
Methanol Oxidation Reaction ◽  
X Ray ◽  
Onset Potential ◽  
Surface Areas

The ternary FePtSn alloy nanoparticles (NPs) were synthesized via a simple programmed microfluidic process, showing a great electrochemical performance in methanol oxidation reaction (MOR). The synthesis process exhibited convenient and spatial-temporal kinetics control of the NPs formation for a narrow size distribution, ultra-small (~2nm) and good dispersion features. The morphology, crystal structure and composition of FePtSn NPs were characterized by transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), powder X-ray diffraction (XRD). FePtSn/C nanocatalyst ink could be further prepared by mixing the as-synthesized or annealed FePtSn NPs with carbon black powder and nafion. Their electrocatalytic performances were tested by the electrochemical work station. By contrast, the annealing treatment made more active sites exposed and facilitated the catalytic performance of FePtSn/C NPs. The electrochemical active surface areas (ECSAs, 42.8m2/g), catalytic activity (If: 588.1 mA/mg-Pt) and electrochemical durability of FePtSn/C nanocatalysts after annealing were greatly improved, comparing with as-synthesized samples and commercial Pt/C nanocatalysts for MOR. In addition, the onset potential of annealed FePtSn/C nanocatalysts was improved, much better than the commercial Pt/C nanocatalysts.

Strategy for stabilizing noble metal nanoparticles without sacrificing active sites

2019 ◽  
Vol 55 (48) ◽  
pp. 6846-6849 ◽  
Author(s):  
Weikang Ji ◽  
Xuyu Wang ◽  
Minni Tang ◽  
Le Yang ◽  
Zebao Rui ◽  
...  
Keyword(s):  
Metal Nanoparticles ◽  
Noble Metal ◽  
Active Sites ◽  
Noble Metal Nanoparticles ◽  
Electronic Interaction ◽  
Pt Nanoparticle ◽  
Support Interaction ◽  
Metal Support Interaction ◽  
Metal Support ◽  
Surface Fluorination

We report a facile surface fluorination strategy for restricting Pt nanoparticle sintering through providing anchoring sites on the TiO2 support and enhancing metal–support interaction via improved electronic interaction without sacrificing the active sites.

scholarly journals Organometallic Nanoparticles Ligated by NHCs: Synthesis, Surface Chemistry and Ligand Effects

Catalysts ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1144 ◽  
Author(s):  
Christian Cerezo-Navarrete ◽  
Patricia Lara ◽  
Luis M. Martínez-Prieto
Keyword(s):  
Metallic Nanoparticles ◽  
Active Sites ◽  
Heterogeneous Catalysts ◽  
Active Surface ◽  
Heterocyclic Carbenes ◽  
Synthetic Methods ◽  
Active Surface Area ◽  
Organometallic Precursor ◽  
Catalytic Applications ◽  
The Many

Over the last 20 years, the use of metallic nanoparticles (MNPs) in catalysis has awakened a great interest in the scientific community, mainly due to the many advantages of this kind of nanostructures in catalytic applications. MNPs exhibit the characteristic stability of heterogeneous catalysts, but with a higher active surface area than conventional metallic materials. However, despite their higher activity, MNPs present a wide variety of active sites, which makes it difficult to control their selectivity in catalytic processes. An efficient way to modulate the activity/selectivity of MNPs is the use of coordinating ligands, which transforms the MNP surface, subsequently modifying the nanoparticle catalytic properties. In relation to this, the use of N-heterocyclic carbenes (NHC) as stabilizing ligands has demonstrated to be an effective tool to modify the size, stability, solubility and catalytic reactivity of MNPs. Although NHC-stabilized MNPs can be prepared by different synthetic methods, this review is centered on those prepared by an organometallic approach. Here, an organometallic precursor is decomposed under H2 in the presence of non-stoichiometric amounts of the corresponding NHC-ligand. The resulting organometallic nanoparticles present a clean surface, which makes them perfect candidates for catalytic applications and surface studies. In short, this revision study emphasizes the great versatility of NHC ligands as MNP stabilizers, as well as their influence on catalysis.

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.

Surfactant-free solution-based synthesis of metallic nanoparticles toward efficient use of the nanoparticles’ surfaces and their application in catalysis and chemo-/biosensing

2013 ◽  
Vol 2 (1) ◽  
pp. 5-25 ◽  
Author(s):  
Hideya Kawasaki
Keyword(s):  
Metal Nanoparticles ◽  
Metallic Nanoparticles ◽  
Active Sites ◽  
Metal Nanoparticle ◽  
Molar Ratio ◽  
Synthesis Methods ◽  
Ionization Mass ◽  
Free Solution ◽  
Effective Utilization ◽  
Stabilizing Agents

AbstractThe choice of stabilizer and the stabilizer-to-precursor ions molar ratio during metal nanoparticle synthesis are important for controlling the shape, size, and dispersion stability of the nanoparticles. However, the active sites on the nanoparticles surfaces may be blocked by the stabilizing agents used, resulting in a less-than-effective utilization of the surfaces. In this review, various surfactant-free solution-based methods of synthesizing metal nanoparticles are described, along with the applications of such nanoparticles in catalysis and sensing. “Surfactant-free” synthesis does not imply truly bare metal nanoparticles synthesis but implies one where the metal nanoparticles are prepared in the absence of additional stabilizing agents such as thiolate and phosphine compounds, surfactants, and polymers. These metal nanoparticles are stabilized by the solvents or the simple ions of the reducing agents or low-molecular-weight salts used. Surfactant-free synthesis of metal nanoparticles via photochemical-, ultrasonochemical-, and laser ablation-mediated synthesis methods is also described. Because of the effective utilization of their surfaces, metal nanoparticles prepared without surfactants, polymers, templates, or seeds are expected to exhibit high performance when used in catalysis (synthetic catalysis and electrocatalysis) and sensing (surface-enhanced Raman scattering (SERS)), surface-assisted laser desorption/ionization-mass spectrometry (SALDI-MS)).

scholarly journals Comparison of the Effect of Polypyrimidine on Catalytic Performance of Polypyrimidine/CNT as Fuel Cell Catalyst Carrier

2019 ◽  
Author(s):  
Naziermu Dongmulati ◽  
Caijin Shi ◽  
Xieraili Maimaitiyiming
Keyword(s):  
Carbon Nanotubes ◽  
Fuel Cell ◽  
Active Sites ◽  
Active Surface ◽  
Catalytic Performance ◽  
Active Surface Area ◽  
Catalyst Carrier ◽  
Fuel Cell Catalyst ◽  
Platinum Particles ◽  
New Type

A new type π-conjugated poly(2,5-didodecyloxy-1,4-diethynyl-phenylene-alt-2-methyl-4,6-pyrimidine) was prepared by Sonogashira polycondensation. A fuel cell catalyst is prepared by depositing platinum particles on carbon nanotubes which was modified with poly(2,5-didodecyloxy-1,4-diethynyl-phenylene-alt-2-methyl-4,6-pyrimidine) and the previously reported poly(2,5-didodecyloxy-1,4-diethynyl-phenylene-alt-2-amino-4,6-pyrimidine). After comparing the two catalysts, it is found that active sites and catalytic performance of catalysts are significantly influenced by the copolymer on the carbon nanotubes which was the catalysis carrier. The electrochemically active surface area (ECSA) of catalysts containing poly(2,5-didodecyloxy-1,4-diethynyl-phenylene-alt-2-methyl-4,6-pyrimidine) was calculated to be 25.5 m2 g-1, which is higher than the ECSA of the poly(2,5-didodecyloxy-1,4-diethynyl-phenylene-alt-2-amino-4,6-pyrimidine) containing catalyst (18.2 m2 g-1). And the first polymer provides better methanol oxidizability and durability than second polymer for catalyst.

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.

Sign in / Sign up

Export Citation Format

Share Document