Metal Catalysts for Heterogeneous Catalysis: From Single Atoms to Nanoclusters and Nanoparticles

Chemical Reviews, Год журнала: 2018, Номер 118(10), С. 4981 - 5079

Опубликована: Апрель 16, 2018

Metal species with different size (single atoms, nanoclusters, and nanoparticles) show catalytic behavior for various heterogeneous reactions. It has been shown in the literature that many factors including particle size, shape, chemical composition, metal–support interaction, metal–reactant/solvent interaction can have significant influences on properties of metal catalysts. The recent developments well-controlled synthesis methodologies advanced characterization tools allow one to correlate relationships at molecular level. In this Review, electronic geometric structures single nanoparticles will be discussed. Furthermore, we summarize applications types reactions, CO oxidation, selective hydrogenation, organic electrocatalytic, photocatalytic We compare results obtained from systems try give a picture how work reactions perspectives future directions toward better understanding entities unifying manner.

Язык: Английский

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Nanomaterials with enzyme-like characteristics (nanozymes): next-generation artificial enzymes (II)

Chemical Society Reviews, Год журнала: 2018, Номер 48(4), С. 1004 - 1076

Опубликована: Дек. 11, 2018

An updated comprehensive review to help researchers understand nanozymes better and in turn advance the field.

Язык: Английский

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Nanozyme: new horizons for responsive biomedical applications

Chemical Society Reviews, Год журнала: 2019, Номер 48(14), С. 3683 - 3704

Опубликована: Янв. 1, 2019

Nanozymes are nanomaterial-based artificial enzymes.

Язык: Английский

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Well-Defined Materials for Heterogeneous Catalysis: From Nanoparticles to Isolated Single-Atom Sites

Chemical Reviews, Год журнала: 2019, Номер 120(2), С. 623 - 682

Опубликована: Дек. 23, 2019

The use of well-defined materials in heterogeneous catalysis will open up numerous new opportunities for the development advanced catalysts to address global challenges energy and environment. This review surveys roles nanoparticles isolated single atom sites catalytic reactions. In second section, effects size, shape, metal-support interactions are discussed nanostructured catalysts. Case studies summarized illustrate dynamics structure evolution under certain reaction conditions. third we syntheses applications atomic anchored on different types supports. final part, conclude by highlighting catalyst gaining a fundamental understanding their active sites.

Язык: Английский

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Selective anaerobic oxidation of methane enables direct synthesis of methanol

Science, Год журнала: 2017, Номер 356(6337), С. 523 - 527

Опубликована: Май 4, 2017

Direct functionalization of methane in natural gas remains a key challenge. We present direct stepwise method for converting into methanol with high selectivity (~97%) over copper-containing zeolite, based on partial oxidation water. The activation helium at 673 kelvin (K), followed by consecutive catalyst exposures to 7 bars and then water 473 K, consistently produced 0.204 mole CH3OH per copper zeolite. Isotopic labeling confirmed as the source oxygen regenerate zeolite active centers renders desorption energetically favorable. On basis situ x-ray absorption spectroscopy, infrared density functional theory calculations, we propose mechanism involving CuII oxide centers, CuI reoxidation concurrent formation hydrogen.

Язык: Английский

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Applications of Zeolites in Sustainable Chemistry

Chem, Год журнала: 2017, Номер 3(6), С. 928 - 949

Опубликована: Дек. 1, 2017

Язык: Английский

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Synergetic interaction between neighbouring platinum monomers in CO2 hydrogenation

Nature Nanotechnology, Год журнала: 2018, Номер 13(5), С. 411 - 417

Опубликована: Март 19, 2018

Язык: Английский

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Catalysis in a Cage: Condition-Dependent Speciation and Dynamics of Exchanged Cu Cations in SSZ-13 Zeolites

Journal of the American Chemical Society, Год журнала: 2016, Номер 138(18), С. 6028 - 6048

Опубликована: Апрель 12, 2016

The relationships among the macroscopic compositional parameters of a Cu-exchanged SSZ-13 zeolite catalyst, types and numbers Cu active sites, activity for selective catalytic reduction (SCR) NOx with NH3 are established through experimental interrogation computational analysis materials across catalyst composition space. Density functional theory, stochastic models, characterizations demonstrate that within synthesis protocols applied here Si:Al ratios, volumetric density six-membered-rings (6MR) containing two Al (2Al sites) is consistent random siting in lattice subject to Löwenstein's rule. Further, exchanged CuII ions first populate these 2Al sites before populating remaining unpaired, or 1Al, as CuIIOH. These distinguished enumerated ex situ vibrational X-ray absorption spectroscopies (XAS) chemical titrations. In operando XAS follow oxidation state coordination environment function environmental conditions including low-temperature (473 K) SCR catalysis rationalized first-principles thermodynamics ab initio molecular dynamics. Experiment theory together reveal respond sensitively exposure conditions, particular species solvated mobilized by under conditions. While spectroscopically chemically distinct away from they exhibit similar turnover rates, apparent activation energies reaction orders at even on frameworks other than SSZ13.

Язык: Английский

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The Direct Catalytic Oxidation of Methane to Methanol—A Critical Assessment

Angewandte Chemie International Edition, Год журнала: 2017, Номер 56(52), С. 16464 - 16483

Опубликована: Июнь 23, 2017

Despite the large number of disparate approaches for direct selective partial oxidation methane, none them has translated into an industrial process. The methane to methanol is a difficult, but intriguing and rewarding, task as it potential eliminate prevalent natural gas flaring by providing novel routes its valorization. This Review considers synthesis derivatives from homogeneous heterogeneous pathways. By establishing severe limitations related catalytic we highlight vastly superior performance systems which produce or incorporate specific measures, such use multicomponent catalysts stabilize methanol. We thereby identify protection being indispensable future research on catalysis.

Язык: Английский

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Small-Pore Zeolites: Synthesis and Catalysis

Chemical Reviews, Год журнала: 2018, Номер 118(11), С. 5265 - 5329

Опубликована: Май 10, 2018

In the past decade or so, small-pore zeolites have received greater attention than large- and medium-pore molecular sieves that historically dominated literature. This is primarily due to commercialization of two major catalytic processes, NOx exhaust removal methanol conversion light olefins, take advantage properties these materials with smaller apertures. Small-pore possess pores are constructed eight tetrahedral atoms (Si4+ Al3+), each time linked by a shared oxygen These eight-member ring (8MR) provide small molecules access intracrystalline void space, e.g., during car cleaning (NOx removal) en route its into while restricting larger molecule entrance departure critical overall catalyst performance. total, there forty-four structurally different zeolites. Forty-one can be synthesized, first synthetic zeolite (KFI, 1948) was in fact material. Although field 8MR chemistry has expanded many directions, progress synthesis framework-specific, leaving insights generalizations difficult realize. review focuses on relevant details all provides some generalized findings related insights. Next, applications where either been commercialized investigations presented, aim providing structure-activity relationships. The ends summary discusses (i) both progress, (ii) list opportunities field, (iii) brief future outlook.

Язык: Английский

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