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Journal ArticleDOI

Selective propane dehydrogenation with single-site CoII on SiO2 by a non-redox mechanism

TL;DR: In this article, the synthesis, characterization, and catalytic performance for gas phase propane dehydrogenation of single-site Co2+ ions supported on silica was reported.
About: This article is published in Journal of Catalysis.The article was published on 2015-02-01 and is currently open access. It has received 160 citations till now. The article focuses on the topics: Dehydrogenation & Extended X-ray absorption fine structure.
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Journal ArticleDOI
TL;DR: Site Heterogeneous Catalysts: Strategies, Methods, Structures, and Activities
Abstract: Site Heterogeneous Catalysts: Strategies, Methods, Structures, and Activities Christophe Copeŕet,*,† Aleix Comas-Vives,† Matthew P. Conley,† Deven P. Estes,† Alexey Fedorov,† Victor Mougel,† Haruki Nagae,†,‡ Francisco Nuñ́ez-Zarur,† and Pavel A. Zhizhko†,§ †Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1−5, CH-8093 Zürich, Switzerland ‡Department of Chemistry, Graduate School of Engineering Science, Osaka University, CREST, Toyonaka, Osaka 560-8531, Japan A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov str. 28, 119991 Moscow, Russia

561 citations

Journal ArticleDOI
01 Sep 2018
TL;DR: A review of plasmonic catalysis can be found in this article, focusing on the underlying physical mechanisms and their application in catalysis, as well as limitations and future perspectives.
Abstract: The demonstrations of visible-light-driven chemical transformations on plasmonic metal nanostructures have led to the emergence of a new field in heterogeneous catalysis known as plasmonic catalysis The excitement surrounding plasmonic catalysis stems from the ability to use the excitation of energetic charge carriers (as opposed to heat) to drive surface chemistry This offers the opportunity to potentially discover new, more selective reaction pathways that cannot be accessed in temperature-driven catalysis In this Review, we provide a fundamental overview of plasmonic catalysis with emphasis on recent advancements in the field It is our objective to stress the importance of the underlying physical mechanisms at play in plasmonic catalysis and discuss possibilities and limitations in the field guided by these physical insights Plasmonic catalysis has recently revolutionized the field of catalysis, promising to achieve improved control over catalytic reactions by targeting specific electronic excitations In this Review, Linic and co-workers discuss the recent advances in the field, focusing on the underlying physical mechanisms and their application in catalysis, as well as limitations and future perspectives

526 citations

Journal ArticleDOI
TL;DR: An approach to break the scaling relationship for propane dehydrogenation by assembling single atom alloys (SAAs) to achieve simultaneous enhancement of propylene selectivity and propane conversion.
Abstract: Noble-metal alloys are widely used as heterogeneous catalysts. However, due to the existence of scaling properties of adsorption energies on transition metal surfaces, the enhancement of catalytic activity is frequently accompanied by side reactions leading to a reduction in selectivity for the target product. Herein, we describe an approach to breaking the scaling relationship for propane dehydrogenation, an industrially important reaction, by assembling single atom alloys (SAAs), to achieve simultaneous enhancement of propylene selectivity and propane conversion. We synthesize γ-alumina-supported platinum/copper SAA catalysts by incipient wetness co-impregnation method with a high copper to platinum ratio. Single platinum atoms dispersed on copper nanoparticles dramatically enhance the desorption of surface-bounded propylene and prohibit its further dehydrogenation, resulting in high propylene selectivity (~90%). Unlike previous reported SAA applications at low temperatures (<400 °C), Pt/Cu SAA shows excellent stability of more than 120 h of operation under atmospheric pressure at 520 °C.

383 citations

Journal ArticleDOI
TL;DR: In this article, a review describes recent advances in the fundamental understandings of the Propane Dehydrogenation (PDH) process in terms of emerging technologies, catalyst development and new chemistry in regulating the catalyst structures and inhibiting the catalyst deactivation.
Abstract: Propylene is an important building block for enormous petrochemicals including polypropylene, propylene oxide, acrylonitrile and so forth. Propane dehydrogenation (PDH) is an industrial technology for direct propylene production which has received extensive attention in recent years. With the development of dehydrogenation technologies, the efficient adsorption/activation of propane and subsequential desorption of propylene on the surfaces of heterogeneous catalysts remain scientifically challenging. This review describes recent advances in the fundamental understandings of the PDH process in terms of emerging technologies, catalyst development and new chemistry in regulating the catalyst structures and inhibiting the catalyst deactivation. The active sites, reaction pathways and deactivation mechanisms of PDH over metals and metal oxides as well as their dependent factors are also analysed and discussed, which is expected to enable efficient catalyst design for minimizing the reaction barriers and controlling the selectivity towards propylene. The challenges and perspectives of PDH over heterogeneous catalysts are also proposed for further development.

222 citations

Journal ArticleDOI
TL;DR: This review article will compare the aspects of single atom catalysis and surface organometallic catalysis by considering several specific catalytic reactions, some of which exist for both fields, whereas others might see mutual overlap in the future.
Abstract: Single atom catalysis (SAC) is a recent discipline of heterogeneous catalysis for which a single atom on a surface is able to carry out various catalytic reactions. A kind of revolution in heterogeneous catalysis by metals for which it was assumed that specific sites or defects of a nanoparticle were necessary to activate substrates in catalytic reactions. In another extreme of the spectrum, surface organometallic chemistry (SOMC), and, by extension, surface organometallic catalysis (SOMCat), have demonstrated that single atoms on a surface, but this time with specific ligands, could lead to a more predictive approach in heterogeneous catalysis. The predictive character of SOMCat was just the result of intuitive mechanisms derived from the elementary steps of molecular chemistry. This review article will compare the aspects of single atom catalysis and surface organometallic catalysis by considering several specific catalytic reactions, some of which exist for both fields, whereas others might see mutual overlap in the future. After a definition of both domains, a detailed approach of the methods, mostly modeling and spectroscopy, will be followed by a detailed analysis of catalytic reactions: hydrogenation, dehydrogenation, hydrogenolysis, oxidative dehydrogenation, alkane and cycloalkane metathesis, methane activation, metathetic oxidation, CO2 activation to cyclic carbonates, imine metathesis, and selective catalytic reduction (SCR) reactions. A prospective resulting from present knowledge is showing the emergence of a new discipline from the overlap between the two areas.

177 citations

References
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Journal ArticleDOI
TL;DR: In this article, a semi-empirical exchange correlation functional with local spin density, gradient, and exact exchange terms was proposed. But this functional performed significantly better than previous functionals with gradient corrections only, and fits experimental atomization energies with an impressively small average absolute deviation of 2.4 kcal/mol.
Abstract: Despite the remarkable thermochemical accuracy of Kohn–Sham density‐functional theories with gradient corrections for exchange‐correlation [see, for example, A. D. Becke, J. Chem. Phys. 96, 2155 (1992)], we believe that further improvements are unlikely unless exact‐exchange information is considered. Arguments to support this view are presented, and a semiempirical exchange‐correlation functional containing local‐spin‐density, gradient, and exact‐exchange terms is tested on 56 atomization energies, 42 ionization potentials, 8 proton affinities, and 10 total atomic energies of first‐ and second‐row systems. This functional performs significantly better than previous functionals with gradient corrections only, and fits experimental atomization energies with an impressively small average absolute deviation of 2.4 kcal/mol.

87,732 citations

Journal ArticleDOI
TL;DR: The effective ionic radii of Shannon & Prewitt [Acta Cryst. (1969), B25, 925-945] are revised to include more unusual oxidation states and coordinations as mentioned in this paper.
Abstract: The effective ionic radii of Shannon & Prewitt [Acta Cryst. (1969), B25, 925-945] are revised to include more unusual oxidation states and coordinations. Revisions are based on new structural data, empirical bond strength-bond length relationships, and plots of (1) radii vs volume, (2) radii vs coordination number, and (3) radii vs oxidation state. Factors which affect radii additivity are polyhedral distortion, partial occupancy of cation sites, covalence, and metallic character. Mean Nb5+-O and Mo6+-O octahedral distances are linearly dependent on distortion. A decrease in cation occupancy increases mean Li+-O, Na+-O, and Ag+-O distances in a predictable manner. Covalence strongly shortens Fe2+-X, Co2+-X, Ni2+-X, Mn2+-X, Cu+-X, Ag+-X, and M-H- bonds as the electronegativity of X or M decreases. Smaller effects are seen for Zn2+-X, Cd2+-X, In2+-X, pb2+-X, and TI+-X. Bonds with delocalized electrons and therefore metallic character, e.g. Sm-S, V-S, and Re-O, are significantly shorter than similar bonds with localized electrons.

51,997 citations

Journal ArticleDOI
TL;DR: In this article, a triple zeta valence (TZV) basis set is presented for Li to Kr. The TZV bases are characterized by typically including a single contraction to describe inner shells and three basis functions for valence shells.
Abstract: Contracted Gaussian basis sets of triple zeta valence (TZV) quality are presented for Li to Kr. The TZV bases are characterized by typically including a single contraction to describe inner shells and three basis functions for valence shells. All parameters—orbital exponents and contraction coefficients—have been determined by minimization of atomic self‐consistent field ground state energies. Advantages and necessary modifications of TZV basis sets are discussed for simple test calculations of molecular energies and nuclear magnetic resonance (NMR) chemical shieldings in treatments with and without inclusion of electron correlation.

7,859 citations

Book
01 Jan 2007
TL;DR: In this article, experimental methods for measuring BDEs are presented for measuring C-H bonds, C-C bonds, and C -C-C-H-C Bonds.
Abstract: Introduction Experimental methods for measuring BDEs BDEs of C-H Bonds BDEs of C-C Bonds BDEs of C-halogen bonds BDEs of O-X bonds BDEs of N-X bonds BDEs of S-, Se-, Te-, and Po-X bonds BDEs of Si-, Ge-, Sn-, and Pb-X bonds BDEs of P-, As-, Sb-, and Bi-X bonds BDEs of H(H+/-)-, Li(Li+/-)-, Na(Na+/-)-, K(K+/-)-, Rb(Rb+/-)-, and Cs(Cs+/-)-X bonds BDEs of Be(Be+)-, Mg(Mg+)-, Ca(Ca+)-, Sr(Sr+)-, Ba(Ba+)-, and Ra-X bonds BDEs of Sc(Sc+)-, Y(Y+)-, La(La+)-, and Ac(Ac+)-X bonds BDEs of Ti(Ti+/-)-, Zr(Zr+)-, and Hf(Hf+)-X bonds BDEs of V(V+/-)-, Nb(Nb+)-, and Ta(Ta+)-X bonds BDEs of Cr(Cr+/-)-, Mo(Mo+/-)-, and W(W+/-)-X bonds BDEs of Mn(Mn+/-)-, Tc-, and Re(Re+)-X bonds BDEs of Fe(Fe+/-)-, Ru(Ru+)-, and Os(Os+)-X bonds BDEs of Co(Co+/-)-, Rh(Rh+)-, and Ir(Ir+)-X bonds BDEs of Ni(Ni+/-)-, Pd(Pd+/-)-, and Pt(Pt+/-)-X bonds BDEs of Cu(Cu+/-)-, Ag(Ag+/-)-, and Au(Au+/-)-X bonds BDEs of Zn(Zn+)-, Cd(Cd+)-, and Hg(Hg+)-X bonds BDEs of B(B+/-)-, Al(Al+/-)-, Ga(Ga+/-)-, In(In+/-)-, and Tl(Tl+/-)-X Bonds BDEs in the C-, Si-, Ge-, Sn-, Pb-clusters and complexes BDEs in the N-, P-, As-, Sb-, Bi-clusters and complexes BDEs in the O-, S-, -Se, and Te-clusters and complexes BDEs in the halogenated molecules, clusters, and complexes BDEs in rare gas atom/ion clusters Heats of formation of atoms, radicals, and ions References (1946 through 2006) Index of compound classes Index of compound names

2,335 citations

Journal ArticleDOI
TL;DR: The study compares different catalysts in terms of the reaction mechanism and deactivation pathways and catalytic performance, as dehydrogenation for the production of light olefins has become extremely relevant.
Abstract: A study is conducted to demonstrate catalytic dehydrogenation of light alkanes on metals and metal oxides. The study provides a complete overview of the materials used to catalyze this reaction, as dehydrogenation for the production of light olefins has become extremely relevant. Relevant factors, such as the specific nature of the active sites, as well as the effect of support, promoters, and reaction feed on catalyst performance and lifetime, are discussed for each catalytic Material. The study compares different catalysts in terms of the reaction mechanism and deactivation pathways and catalytic performance. The duration of the dehydrogenation step depends on the heat content of the catalyst bed, which decreases rapidly due to the endothermic nature of the reaction. Part of the heat required for the reaction is introduced to the reactors by preheating the reaction feed, additional heat being provided by adjacent reactors that are regenerating the coked catalysts.

1,306 citations