The present letter describes an atomic scale investigation of a chemical reaction for selective hydrogen production. This clean fuel is a sustainable energy source. Because electron transfer is the key to such reactions, accurate methods based on quantum theory are used. The reaction between water and carbon monoxide has been used industrially with metal catalysts, usually Platinum. There is a considerable economic and environmental challenge underpinning this application of a fundamental process limited by bond dissociation. That is the process often limiting reaction rates for industrial catalysis. Most mainstream quantum approaches fail to greater or lesser degree in the description of bond dissociation. The present work presents a promising alternative: the initial analysis of a considerable mass of statistical data generated by the atomic-scale Quantum Monte Carlo method to very stringent statistical accuracy for essential information on the hydrogen production via the water-gas shift reaction with platinum catalyst.
This is encouraging for establishing less well-known benchmark values of industrial reaction barriers on Pt(111).
Selective electrochemical generation of hydrogen peroxide from water oxidation
水是生命之源，是人类生存的根本，但仍有10亿多人无法获得清洁饮用水。目前的水处理技术（例如管道水、处理水）依赖于时间和资源密集型的集中解决方案。在这项工作中，我们提出了一个分散的设备的概念，可以利用阳光分解水为氢和过氧化氢。过氧化氢可以氧化有机物，同时氢气冒泡。在实现该装置时，我们需要一种电催化剂，该电催化剂可以氧化水，同时抑制有害的氧析出并形成过氧化氢。使用密度泛函理论计算，我们表明，吸附的OH $^*$的自由能可以被用作一个描述符，以筛选之间的选择性趋势的2E $^-$水氧化H $_2$ O $_2$和4 E $^-$氧化O $_2$。我们表明，结合氧中间体足够弱的材料，如SnO $_2$，可以激活过氧化氢的演变。我们提出了一个合理的设计原则，在电化学水氧化的选择性，并确定新材料候选人，可以执行H $_2$ O $_2$进化选择性。
The rational design of hydrogen evolution reaction (HER) electrocatalysts which are competitive with platinum is an outstanding challenge to make power-to-gas technologies economically viable. Here, we introduce the delafossites PdCrO$_2$, PdCoO$_2$ and PtCoO$_2$ as a new family of electrocatalysts for the HER in acidic media. We show that in PdCoO$_2$ the inherently strained Pd metal sublattice acts as a pseudomorphic template for the growth of a strained (by +2.3%) Pd rich capping layer under reductive conditions. The surface modification continuously improves the electrocatalytic activity b…
Catalysts of carbon monoxide oxidation were synthesized by deposition of platinum on titanium nitride (TiN). Two substrates with an average particle size of 18 and 36 nm were obtained by hydrogen reduction of titanium tetrachloride in a stream of microwave plasma of nitrogen. The surface of the catalysts was studied by X-ray photoelectron spectroscopy (XPS). The CO oxidation rate on the 9-15 wt.% Pt loaded TiN catalysts was found to be 120 times higher than that on platinum black with a specific surface of 30 m2/g. Such catalysts are promising for use in catalytic air purification systems.
Chemically-reduced graphene-oxide-supported gold or iridium nanoparticles are considered here as active carriers for dispersed platinum with an ultimate goal of producing improved catalysts for electroreduction of oxygen in acid medium. Comparison is made to the analogous systems not utilizing reduced graphene oxide. High electrocatalytic activity of platinum (loading up to 30 μg cm-2) dispersed over the reduced-graphene oxide-supported Au (up to 30 μg cm-2) or Ir (up to 1.5 μg cm-2) nanoparticles toward reduction of oxygen has been demonstrated using cyclic and rotating ring-disk electrode (R…
A sustainable photocatalytic pathway for concurrent hydrogen and value-added chemical production utilizing microalgae as bio-scavenger in water
WPI, International Institute for Carbon Neutral Energy Research (WPI-I2CNER), Kyushu University（九州大学碳中和能源研究国际高等研究院（WPI-I2CNER））；Department of Automotive Science, Graduate School of Integrated Frontier Sciences, Kyushu University（九州大学前沿融合科学研究生院汽车科学系）；Laboratório de Biotecnologia BraPhyto, Faculdade de Ciências Aplicadas (FCA), Universidade Estadual de Campinas (UNICAMP)（坎皮纳斯州立大学（UNICAMP）应用科学学院BraPhyto生物技术实验室）；Mitsui Chemicals, Inc. - Carbon Neutral Research Center (MCI-CNRC), Kyushu University（三井化学株式会社-碳中和研究中心（MCI-CNRC））
Quantum proton tunneling (QPT) in the two representative multi-electron/-proton transfer electrode processes, i.e. hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR), was investigated by using polycrystalline platinum (pcPt) and gold (pcAu) electrodes at 298 kelvin (K). In order to observe quantum effects in the electrode processes, the hydrogen/deuterium kinetic isotope effect constant ratio (= KH/D) was measured in a variety of conditions. In this Contribution, it is shown that the QPT in surface electrochemical system is highly affected by a choice of system. Although sev…
Hydrogen production as a clean, sustainable replacement for fossil fuels is gathering pace. Doubling the capacity of Paris-CDG airport has been halted, even with the upcoming Olympic Games, until hydrogen powered planes can be used. It is thus timely to work on catalytic selective hydrogen production and optimise catalyst structure. Over 90 % of all chemical manufacture uses a solid catalyst. This work describes adsorption of carbon-monoxide (CO) on platinum thin films, supported by cheap Al(111). CO reacts with water to produce hydrogen (water-gas shift). Quantum Monte Carlo methods are the o…
Electrocatalysis plays a crucial role in realizing the transition towards green energy, driving research directions from hydrogen generation to carbon dioxide reduction. Understanding electrochemical reactions is crucial to improve their efficiency and to bridge the gap toward a sustainable zero-carbon future. Surface-enhanced infrared absorption spectroscopy (SEIRAS) is a suitable method for investigating these processes because it can monitor with chemical specificity the mechanisms of the reactions. However, it remains difficult to detect many relevant aspects of electrochemical reactions s…
Predictive-quality computational modeling of heterogeneously catalyzed reactions has emerged as an important tool for the analysis and assessment of activity and activity trends. In contrast, more subtle selectivities and selectivity trends still pose a significant challenge to prevalent microkinetic modeling approaches that typically employ a mean-field approximation (MFA). Here, we focus on CO hydrogenation on Rh catalysts with the possible products methane, acetaldehyde, ethanol and water. This reaction has already been subject to a number of experimental and theoretical studies with confli…
Over 90 % of all chemical manufacture uses a solid catalyst. Related work thus responds to major societal demand. This study is of water-gas shift on platinum for hydrogen production. The close-packed Pt(111) surface catalyses this process. Many chemical reactions involve bond-dissociation. This is also true for reactions at solid surfaces, in which the dissociation step is often limiting but facilitated in comparison to gas phase reaction channels. Since bond-breaking is poorly described by Hartree-Fock and DFT methods, this work adopts Quantum Monte Carlo (QMC) methodology. QMC is a stochast…
Quantum Dynamical and isotopic effects for Hydrogen isotopes scattering at W(110) surface
Université de Bordeaux（波尔多大学）；Donostia International Physics Center (DIPC)（圣塞巴斯蒂安国际物理中心）；Euskal Herriko Unibertsitatea EHU（巴斯克地区大学）；Université Paris-Saclay（巴黎萨克雷大学）；CNRS（法国国家科学研究中心）；Université de Lorraine（洛林大学）
