与可靠的实验相比,新的第一性原理方法对金属表面反应路径上关键点的衡量标准是化学准确性。这意味着活化势垒的值需要在1 kcal/mol以内。量子蒙特卡罗(QMC)是一个有前途的(虽然冗长)的第一性原理方法,我们现在已经超越了这些系统的QMC基准的曙光,因为在两个改进的QMC研究\cite{hog0, kdd2}中已经研究了Cu(111)上的氢解离,具有相当足够的精度。铂和铜需要使用的赝势在这些计算中,我们表明,那些铂的问题比那些铜,特别是QMC工作。本文测定了氢原子和氢分子在Pt(111)表面的物理吸附能。这些系统被用来作为渐近线,以确定反应障碍。因此,它们必须涉及干净的Pt(111)表面和孤立的氢原子或分子。以前的工作给出了氢在Pt(111)上解离的活化能垒。所用方法为最新技术水平({ \it ab initio})QMC。该屏障与最近的特定反应参数(SRP-DFT)计算(适合测量值\cite{iran})的化学准确性一致。结果给出氢在Pt(111)上的解离势垒为5.4 kcal/mol(QMC和6.2,通过SRP-DFT),QMC标准误差低于0.99 kcal/mol。这对于在Pt(111)上建立不太知名的工业反应势垒基准值是令人鼓舞的。
英文摘要:
The yardstick of new first-principles approaches to key points on reaction paths at metal surfaces is chemical accuracy compared to reliable experiment. By this we mean that such values as the activation barrier are required to within 1 kcal/mol. Quantum Monte Carlo (QMC) is a promising (albeit lengthy) first-principles method for this and we are now beyond the dawn of QMC benchmarks for these systems, since hydrogen dissociation on Cu(111) has been studied with quite adequate accuracy in two improving QMC studies \cite{hog0, kdd2}. Pt and Cu require the use of pseudo-potentials in these calculations and we show that those of Pt are less problematic than those for Cu, particularly for QMC work. This work determines physisorption energies for hydrogen atoms and molecules on Pt(111). These systems are used as asymptotes to determine reaction barriers. As such, they must be referred to clean Pt(111) surfaces and the isolated hydrogen atom or molecule. Previous work gave the activation barrier to hydrogen dissociation on Pt(111) using the bridging geometry. The method used is state-of-the-art ({\it ab initio}) QMC. This barrier agrees to better than chemical accuracy with a recent Specific Reaction Parameter (SRP-DFT) calculation, fitted to measurement \cite{iran}. The results give the dissociation barrier for hydrogen on Pt(111) as 5.4 kcal/mol (QMC and 6.2 by SRP-DFT) with a QMC standard error below 0.99 kcal/mol. This is encouraging for establishing less well-known benchmark values of industrial reaction barriers on Pt(111).
The 3d Transition Metal Single Atom Catalysis for Prominent Adsorption Performance Towards Cr(VI) : A First Principle Study
通过合适的氧化剂和纳米催化剂在污染土壤和水中将Cr(VI)还原为Cr(III)的还原反应因其环境效益而受到广泛关注。单原子催化剂作为一种新兴的催化剂,在同时吸附去除Cr(VI)方面显示出巨大的潜力。在这项工作中,我们研究了3d过渡金属(从Sc到Zn)SAC的吸附效率,通过理论方法去除Cr(VI)。采用密度泛函理论(DFT)研究了Cr(VI)(H2 CrO 4和Cr2 O 72-)在活性炭上的吸附行为. Ti-N-C对H2 CrO 4和Cr2 O 72-具有良好的去除性能,对水的净化具有重要的环保意义。此外,我们的研究结果表明,H2 CrO 4吸附的SAC系统的结合能被发现是远远小于为Cr2 O 72-吸附,表明还原Cr(VI)在Cr2 O 72-是积极有利的比,Cr(VI)在H2 CrO 4。
Paired Ru-O-Mo ensemble for efficient and stable alkaline hydrogen evolution reaction
碱性介质中的电催化析氢反应是一种很有前途的电化学能量转换方法。钌(Ru)是一种高效的HER催化剂,但由于其表面对H2O的吸附量较低,导致H2O解离过程缓慢,影响了其在碱性HER中的性能。通过简单的热处理工艺制备了具有Ru-O-Mo位的Ru/MoO 2催化剂,并通过透射电子显微镜(TEM)和扩展X射线吸收精细结构(EXAFS)研究了Ru-O-Mo界面的形成。通过傅里叶变换红外光谱(FTIR)和水吸附实验,证明了Ru-O-Mo中心对水的吸附能力是Ru催化剂的10倍。具有Ru-O-Mo位点的催化剂在1 M KOH电解质中在10 mA cm-2下表现出16 mV的最先进的过电位,表明比先前最好的Ru(59 mV)和商业Pt(31 mV)催化剂降低了三倍。我们证明了这些性能的稳定性超过40小时没有下降。这些结果为设计高效稳定的催化剂开辟了一条新的途径。
Why Do Weak-Binding M-N-C Single-Atom Catalysts Possess Anomalously High Oxygen Reduction Activity?
Advanced Institute for Materials Research (WPI-AIMR), Tohoku University(东北大学先进材料研究所);School of Chemical and Biomolecular Engineering, The University of Sydney(悉尼大学化学与生物分子工程学院);State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University(上海交通大学机械系统振动国家重点实验室)
Using a dual plasma process to produce cobalt--polypyrrole catalysts for the oxygen reduction reaction in fuel cells -- part I: characterisation of the catalytic activity and surface structure
介绍了一种新的双等离子体涂层工艺,用于制备燃料电池中氧还原反应的无铂催化剂。用各种方法分析由此产生的催化剂。通过循环伏安法、旋转环电极和旋转环盘电极进行电化学表征。由此获得的不同的催化剂的表面孔隙率的特征在于与氮气吸附技术和扫描电子显微镜用于确定膜的生长机制。它表明,催化活性化合物可以用这种双等离子体工艺生产。此外,催化活性可以通过改变等离子体工艺参数而显著变化。计算了生成的H $_2$ O $_2$的量,并表明2电子机理是主要的。等离子体涂覆机制不会显著改变所用碳载体的表面BET面积和孔径分布。此外,所产生的薄膜的扫描电子显微镜照片,并示出的柱状生长机制的偏好。通过使用不同的碳作为载体,它表明,有很强的依赖性的催化活性,这可能是有关的碳的化学性质。
Benchmarking of Oxygen Adsorption using TPD Spectroscopy for Accurate DFT Prediction of ORR on Anatase Titanium Dioxide (101)
The Institute for Solid State Physics, The University of Tokyo(东京大学固体离子体研究所);Academic Assembly (Faculty of Science), Yamagata University(山形大学理学部);RIKEN(理化学研究所)
University of Illinois(伊利诺伊大学);Materials Research Laboratory, University of Illinois(伊利诺伊大学材料研究实验室);Beckman Institute for Advanced Science and Technology, University of Illinois(伊利诺伊大学贝克曼先进科学技术研究所)
The Key Steps and Distinct Performance Trends of Pyrrolic vs. Pyridinic M-N-C Catalysts in Electrocatalytic Nitrate Reduction
Advanced Institute for Materials Research (WPI-AIMR), Tohoku University(东北大学物质材料研究创新世界首脑研究所);School of Chemical and Biomolecular Engineering, The University of Sydney(悉尼大学化学与生物分子工程学院);State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences(中国科学院长春应用化学研究所稀土资源利用国家重点实验室);School of Applied Chemistry and Engineering, University of Science and Technology of China(中国科学技术大学应用化学与工程学院)
Enhancing Oxygen Reduction Reaction on Pt-Based Electrocatalysts through Surface Decoration for Improved OH Reduction Equilibrium and Reduced H2O Adsorption
Unravelling Distance-Dependent Inter-Site Interactions and Magnetic Transition Effects of Heteronuclear Single Atom Catalysts on Electrochemical Oxygen Reduction
Catalysis distillation neural network for the few shot open catalyst challenge
Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology(广西石化资源加工及过程强化技术重点实验室);School of Chemistry and Chemical Engineering, Guangxi University(广西大学化学化工学院)