发布求助
文献互助 智能选刊 最新文献

Advances in Physical Chemistry最新文献

筛选
英文 中文
Potential Energy Surfaces for Reactions of X Metal Atoms (X = Cu, Zn, Cd, Ga, Al, Au, or Hg) with YH4 Molecules (Y = C, Si, or Ge) and Transition Probabilities at Avoided Crossings in Some Cases X金属原子(X = Cu, Zn, Cd, Ga, Al, Au或Hg)与YH4分子(Y = C, Si或Ge)反应的势能面和某些情况下避免交叉的跃迁概率
Advances in Physical Chemistry Pub Date : 2012-01-18 DOI: 10.1155/2012/720197
O. Novaro, María del Alba Pacheco-Blas, J. Pacheco-Sánchez
{"title":"Potential Energy Surfaces for Reactions of X Metal Atoms (X = Cu, Zn, Cd, Ga, Al, Au, or Hg) with YH4 Molecules (Y = C, Si, or Ge) and Transition Probabilities at Avoided Crossings in Some Cases","authors":"O. Novaro, María del Alba Pacheco-Blas, J. Pacheco-Sánchez","doi":"10.1155/2012/720197","DOIUrl":"https://doi.org/10.1155/2012/720197","url":null,"abstract":"We review ab initio studies based on quantum mechanics on the most important mechanisms of reaction leading to the C–H, Si–H, and Ge–H bond breaking of methane, silane, and germane, respectively, by a metal atom in the lowest states in Cs symmetry: X(2nd excited state, 1st excited state and ground state)","PeriodicalId":7371,"journal":{"name":"Advances in Physical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83727075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 8
New ab Initio Potential Energy Surfaces for the Renner-Teller Coupled and States of CH2 CH2的Renner-Teller耦合和态的新的从头算势能面
Advances in Physical Chemistry Pub Date : 2012-01-12 DOI: 10.1155/2012/236750
Haitao Ma, C. Zhang, Zhijun Zhang, Xiao-jun Liu, W. Bian
{"title":"New ab Initio Potential Energy Surfaces for the Renner-Teller Coupled and States of CH2","authors":"Haitao Ma, C. Zhang, Zhijun Zhang, Xiao-jun Liu, W. Bian","doi":"10.1155/2012/236750","DOIUrl":"https://doi.org/10.1155/2012/236750","url":null,"abstract":"New ab initio potential energy surfaces (PESs) for the two lowest-lying singlet ′ and ′′ electronic states of CH2, coupled by the Renner-Teller (RT) effect and meant for the spectroscopic study, are presented. The surfaces are constructed using a dual-level strategy. The internally contracted multireference configuration interaction calculations with the Davidson correction, using the aug-cc-pVQZ basis set, are employed to obtain 3042 points at the lower level. The core and core-valence correlation effects are taken into account in the ab initio calculations with a modified optimized aug-cc-pCVQZ basis set for the higher-level points. The analytical representations of these PESs, with the inclusion of the nonadiabatic RT terms, are obtained by the nonlinear least-squares fit of the calculated points to three-body expansion. Quantum dynamical calculations are performed on these PESs, and the computed vibronic energy levels for the two singlet electronic states are in excellent agreement with experiment.","PeriodicalId":7371,"journal":{"name":"Advances in Physical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88099973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 5
Quantum Instanton Evaluations of the Thermal Rate Constants forComplex Systems 复杂系统热速率常数的量子瞬态计算
Advances in Physical Chemistry Pub Date : 2012-01-01 DOI: 10.1155/2012/483504
Yi Zhao, Wenji Wang
{"title":"Quantum Instanton Evaluations of the Thermal Rate Constants forComplex Systems","authors":"Yi Zhao, Wenji Wang","doi":"10.1155/2012/483504","DOIUrl":"https://doi.org/10.1155/2012/483504","url":null,"abstract":"Quantum instanton (QI) approximation is recently proposed for the evaluations of the chemical reaction rate constants with use of full dimensional potential energy surfaces. Its strategy is to use the instanton mechanism and to approximate time-dependent quantum dynamics to the imaginary time propagation of the quantities of partition function. It thus incorporates the properties of the instanton idea and the quantum effect of partition function and can be applied to chemical reactions of complex systems. In this paper, we present the QI approach and its applications to several complex systems mainly done by us. The concrete systems include, (1) the reaction of , (2) the reaction of , (3) H diffusion on Ni(100) surface; and (4) surface-subsurface transport and interior migration for H/Ni. Available experimental and other theoretical data are also presented for the purpose of comparison.","PeriodicalId":7371,"journal":{"name":"Advances in Physical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91280428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 4
Diffraction Measurements and Equilibrium Parameters 衍射测量和平衡参数
Advances in Physical Chemistry Pub Date : 2011-12-28 DOI: 10.1155/2011/864714
V. A. Sipachev
{"title":"Diffraction Measurements and Equilibrium Parameters","authors":"V. A. Sipachev","doi":"10.1155/2011/864714","DOIUrl":"https://doi.org/10.1155/2011/864714","url":null,"abstract":"Structural studies are largely performed without taking into account vibrational effects or with incorrectly taking them into account. The paper presents a first-order perturbation theory analysis of the problem. It is shown that vibrational effects introduce errors on the order of 0.02 A or larger (sometimes, up to 0.1-0.2 A) into the results of diffraction measurements. Methods for calculating the mean rotational constants, mean-square vibrational amplitudes, vibrational corrections to internuclear distances, and asymmetry parameters are described. Problems related to low-frequency motions, including torsional motions that transform into free rotation at low excitation levels, are discussed. The algorithms described are implemented in the program available from the author (free).","PeriodicalId":7371,"journal":{"name":"Advances in Physical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87806414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 7
Potential Energy Surfaces Using Algebraic Methods Based on Unitary Groups 基于酉群的势能曲面代数方法
Advances in Physical Chemistry Pub Date : 2011-12-21 DOI: 10.1155/2011/593872
R. Lemus
{"title":"Potential Energy Surfaces Using Algebraic Methods Based on Unitary Groups","authors":"R. Lemus","doi":"10.1155/2011/593872","DOIUrl":"https://doi.org/10.1155/2011/593872","url":null,"abstract":"This contribution reviews the recent advances to estimate the potential energy surfaces through algebraic methods based on the unitary groups used to describe the molecular vibrational degrees of freedom. The basic idea is to introduce the unitary group approach in the context of the traditional approach, where the Hamiltonian is expanded in terms of coordinates and momenta. In the presentation of this paper, several representative molecular systems that permit to illustrate both the different algebraic approaches as well as the usual problems encountered in the vibrational description in terms of internal coordinates are presented. Methods based on coherent states are also discussed.","PeriodicalId":7371,"journal":{"name":"Advances in Physical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79970067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 12
Mechanisms of Oxidation-Reduction Reactions Can Be Predicted by the Magnetic Isotope Effect 磁同位素效应可以预测氧化还原反应的机理
Advances in Physical Chemistry Pub Date : 2011-12-20 DOI: 10.1155/2011/450325
V. N. Epov
{"title":"Mechanisms of Oxidation-Reduction Reactions Can Be Predicted by the Magnetic Isotope Effect","authors":"V. N. Epov","doi":"10.1155/2011/450325","DOIUrl":"https://doi.org/10.1155/2011/450325","url":null,"abstract":"Magnetic isotope effect can cause mass-independent isotope fractionation, which can be used to predict the mechanisms of chemical reactions. In this critical paper, the isotope fractionation caused by magnetic isotope effect is used to understand detailed mechanisms of oxidation-reduction reactions for some previously published experimental data. Due to the rule that reactions are allowed for certain electron spin state, and forbidden for others, magnetic isotopes show chemical anomalies during these reactions due to the hyperfine interaction of the nuclear spin with the electron spin. It is demonstrated that compound or complex in paramagnetic (triplet) state accepts electrons during the reactions of electron transfer. Also, ligand field strength is responsible for the magnitude and the sign of the mass-independent fractionation. From another side, magnetic isotope effect can be used to predict the ligand strength. According to the proposed mechanism, the following parameters are important for the sign and magnitude of mass-independent isotope fractionation caused by magnetic isotope effect (due to predominant either singlet-triplet or triplet-singlet evolution): (i) the arrangement of the ligands around the metal ion; (ii) the nature (strength) of the ligands surrounding the metal ion; (iii) presence/absence of light. The suggested approach is applied to understand Hg reduction by dissolved organic carbon or by Sn(II).","PeriodicalId":7371,"journal":{"name":"Advances in Physical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87714372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Sequential Electrodeposition of Platinum-Ruthenium at Boron-Doped Diamond Electrodes for Methanol Oxidation 铂钌在掺硼金刚石电极上的序贯电沉积用于甲醇氧化
Advances in Physical Chemistry Pub Date : 2011-11-29 DOI: 10.1155/2011/679246
I. González-González, Camille Lorenzo-Medrano, C. Cabrera
{"title":"Sequential Electrodeposition of Platinum-Ruthenium at Boron-Doped Diamond Electrodes for Methanol Oxidation","authors":"I. González-González, Camille Lorenzo-Medrano, C. Cabrera","doi":"10.1155/2011/679246","DOIUrl":"https://doi.org/10.1155/2011/679246","url":null,"abstract":"Sequential electrodeposition of Pt and Ru on boron-doped diamond (BDD) films, in 0.5 M H2SO4 by cyclic voltammetry, has been prepared. The potential cycling, in the aqueous solutions of the respective metals, was between 0.00 and 1.00 V versus Ag/AgCl. The catalyst composites, Pt and PtRu, deposited on BDD film substrates, were tested for methanol oxidation. The modified diamond surfaces were also characterized by scanning electron microscopy-X-ray fluorescence-energy dispersive spectroscopy, X-ray photoelectron spectroscopy, and Auger electron spectroscopy. The scanning Auger electron spectroscopy mapping showed the ruthenium signal only in areas where platinum was electrodeposited. Ruthenium does not deposit on the oxidized diamond surface of the boron-doped diamond. Particles with 5–10% of ruthenium with respect to platinum exhibited better performance for methanol oxidation in terms of methanol oxidation peak current and chronoamperometric current stability. The electrogenerated •OH radicals on BDD may interact with Pt surface, participating in the methanol oxidation as shown in oxidation current and the shift in the peak position. The conductive diamond surface is a good candidate as the support for the platinum electrocatalyst, because it ensures catalytic activity, which compares with the used carbon, and higher stability under severe anodic and cathodic conditions.","PeriodicalId":7371,"journal":{"name":"Advances in Physical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83637326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 10
Contrast and Synergy between Electrocatalysis and Heterogeneous Catalysis 电催化与多相催化的对比与协同作用
Advances in Physical Chemistry Pub Date : 2011-11-24 DOI: 10.1155/2011/907129
A. Wiȩckowski, M. Neurock
{"title":"Contrast and Synergy between Electrocatalysis and Heterogeneous Catalysis","authors":"A. Wiȩckowski, M. Neurock","doi":"10.1155/2011/907129","DOIUrl":"https://doi.org/10.1155/2011/907129","url":null,"abstract":"The advances in spectroscopy and theory that have occurred over the past two decades begin to provide detailed in situ resolution of the molecular transformations that occur at both gas/metal as well as aqueous/metal interfaces. These advances begin to allow for a more direct comparison of heterogeneous catalysis and electrocatalysis. Such comparisons become important, as many of the current energy conversion strategies involve catalytic and electrocatalytic processes that occur at fluid/solid interfaces and display very similar characteristics. Herein, we compare and contrast a few different catalytic and electrocatalytic systems to elucidate the principles that cross-cut both areas and establish characteristic differences between the two with the hope of advancing both areas.","PeriodicalId":7371,"journal":{"name":"Advances in Physical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77447752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 26
Platinum Monolayer Electrocatalysts for the Oxygen Reduction Reaction: Improvements Induced by Surface and Subsurface Modifications of Cores 用于氧还原反应的铂单层电催化剂:芯的表面和亚表面修饰引起的改进
Advances in Physical Chemistry Pub Date : 2011-11-20 DOI: 10.1155/2011/530397
Yun Cai, R. Adzic
{"title":"Platinum Monolayer Electrocatalysts for the Oxygen Reduction Reaction: Improvements Induced by Surface and Subsurface Modifications of Cores","authors":"Yun Cai, R. Adzic","doi":"10.1155/2011/530397","DOIUrl":"https://doi.org/10.1155/2011/530397","url":null,"abstract":"This paper demonstrates that the ORR activity of PtML electrocatalysts can be further improved by the modification of surface and subsurface of the core materials. The removal of surface low-coordination sites, generation (via addition or segregation) of an interlayer between PtML and the core, or the introduction of a second metal component to the subsurface layer of the core can further improve the ORR activity and/or stability of PtML electrocatalysts. These modifications generate the alternation of the interactions between the substrate and the PtML, involving the changes on both electronic (ligand) and geometric (strain) properties of the substrates. The improvements resulted from the application of these approaches provide a new perspective to designing of the new generation PtML electrocatalysts.","PeriodicalId":7371,"journal":{"name":"Advances in Physical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73778029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 33
Potentiostatic Testing of Oxygen Reduction on Polymer Carbon Electrodes 聚合物碳电极上氧还原的恒电位测试
Advances in Physical Chemistry Pub Date : 2011-11-15 DOI: 10.1155/2011/414108
C. Sequeira, D. Santos
{"title":"Potentiostatic Testing of Oxygen Reduction on Polymer Carbon Electrodes","authors":"C. Sequeira, D. Santos","doi":"10.1155/2011/414108","DOIUrl":"https://doi.org/10.1155/2011/414108","url":null,"abstract":"The preparation of polymer carbon electrocatalysts by the controlled pyrolysis of polyfurfuryl alcohol polymer is described. Potentiostatic testing in oxygen-saturated KOH electrolytes is performed, and electrokinetic properties of the electrodes prepared from the electrocatalysts are presented and discussed. It is revealed that a pure polymer carbon electrode pyrolysed in powder form possesses a very high active area, displaying higher catalytic activity than a polymer pyrolysed in bulk. Suitable reduction mechanisms are proposed.","PeriodicalId":7371,"journal":{"name":"Advances in Physical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83179904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
首页 上一页 下一页 尾页
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整，为了账户安全，请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
请完成安全验证×
相关产品
×
本文献相关产品
联系我们：info@booksci.cn Book学术提供免费学术资源搜索服务，方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号：481959085
Book学术官方微信