Results 11 to 20 of about 14,679 (214)
Rare Metals, EarlyView.ABSTRACT Ni3S2 has emerged as a promising catalyst for the electrochemical oxidation of biomass‐derived 5‐hydroxymethylfurfural (HMF) to 2,5‐furandicarboxylic acid (FDCA), driven by its distinctive physicochemical properties. However, its practical catalytic efficiency is severely hindered by abundant electrochemically inactive surface sites and poor ...
Cheng‐Feng Yi +5 more
wiley +1 more source
A DFT Study on C-H Bond Activation of Methane by CeO2 and CeO2-doped with Metal Cations [PDF]
, 2015 甲烷是天然气的主要成分，是燃料和化学品中非常出色的原材料，但甲烷又是非常稳定的分子，其活化常需较高的温度，因此，研究有效活化甲烷，特别是较低温下转化甲烷的催化剂，具有理论和实际的研究意义。近年来，研究表明二氧化铈基纳米催化剂具有良好的低温活化甲烷性能，但其活性中心本质和活化机理尚不很清楚。为此，我们采用密度泛函理论(DFT)方法，对二氧化铈及掺杂不同金属阳离子的二氧化铈体系活化甲烷C-H进行了计算研究。其主要研究内容和结果如下： 1.以(CeO2)m(m=1-3)团簇为模型对甲烷C ...
陈蓉芳
core
Rare Metals, EarlyView.ABSTRACT This study elucidates the oxidation mechanisms governing Y/Hf‐doped AlCoCrFeNiTi high‐entropy alloys (HEAs) and reveals the pivotal role of fabrication processes in dictating high‐temperature oxidation behavior. We demonstrate that casting and spark plasma sintering (SPS) promote Y/Hf segregation, resulting in heterogeneous oxide formation and
Huaqing Yi +5 more
wiley +1 more source
New Catalysts for the Photocatalytic Reduction of Carbon Dioxide to C1 Organic Compounds [PDF]
, 2011 Photocatalytic reduction of carbon dioxide (CO2) has recently been identified as one of the five notable research areas in catalysis because it simultaneously reduces carbon emissions while storing clean, “green” solar energy in organic compounds.
Hailey, Anna
core +1 more source
Rare Metals, EarlyView.ABSTRACT SnTe is considered a potential alternative to PbTe for thermoelectric applications. However, excessive carrier concentration and thermal conductivity result in poor thermoelectric performance. Herein, p‐type SnTe‐based materials Sn0.8‐xMn0.1Pb0.1SbxTe were synthesized, and the combined effects of Sb, Mn, and Pb were systematically investigated.
Jun‐Xiang Zhang +10 more
wiley +1 more source
Synthesis and Characterization of Lanthanum-based Nano Catalysts for Oxidative Coupling of Methane [PDF]
, 2015 甲烷氧化偶联(OCM)是实现甲烷直接转化制C2烃的重要途径，研发有效的催化剂，使甲烷活化温度降低，目标产物深度氧化得到抑制，是一极富挑战性的课题。纳米催化剂，因粒径小，比表面大，分散性好，表面原子配位未饱和程度高，因而具有较强的选择活化反应物分子的能力，受到了人们的普遍关注。因此，本文以镧氧化物为研究对象，从纳米催化剂的制备、改性及阴阳离子调变(掺杂)等角度出发，对催化剂的构效关系进行了研究。主要结果总结如下： 1.催化剂的分散性和酸碱性：通过于浸渍液中添加聚乙烯吡咯烷酮(PVP ...
侯玉慧
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Rare Metals, EarlyView.ABSTRACT Enhancing the performance of phosphor materials for wide‐color‐gamut and high‐brightness phosphor‐converted light‐emitting diodes (pc‐LEDs) represents a critical materials challenge. Improving quantum efficiency (QE) under concentration quenching constraints and maintaining thermal stability remain primary objectives.
Yuhan Zhou +3 more
wiley +1 more source
Dianci bileiqi, 2023 笔者主要研究了Fe3+离子掺杂引入对ZnO基压敏电阻微观结构及综合电气性能的影响。实验结果表明，随着铁离子掺杂量的增加，ZnO压敏电阻的电位梯度持续不断升高，非线性系数先升高而后降低，漏流先减小再增大，压比逐渐增加。分析认为，掺杂少量Fe3+时，可作为受主元素提高表面态密度，从而使非线性系数升高；随着掺杂量的增加，Fe3+转变为Fe2+进入ZnO晶粒内部，作为替位离子取代了部分Zn2+,由于r(Fe2+)>r(Zn2+),该取代产生了压应力对ZnO晶格产生挤压，减小晶格空隙，从而阻止了其他掺杂离子的进入，
李竹韵 +6 more
doaj
Synthesis of Ⅱ-Ⅵ(ZnO,CdSe) nanostructured materials and its application as photodetector [PDF]
, 2015 本文的研究内容主要分为两个部分：一ZnO纳米材料的制备及其在光电探测领域内的应用；二基于CdSe材料的光电导探测器的研制。 PartAZnO纳米材料的制备及其在光电探测领域内的应用 本部分的研究工作与成果如下： 一:研究不同激光能量密度的248nm脉冲激光对ZnO材料的影响，发现随着能量密度的增加，制备的ZnO薄膜材料的结构发生变化，当能量密度达到2.5J/cm2时，ZnO薄膜变成纳米片结构材料，其原因可能是来自高能量密度激光产生的非线性效应。 二 ...
徐强
core
Rare Metals, EarlyView.ABSTRACT TiFe‐based hydrogen storage alloys have garnered significant attention because of their cost‐effectiveness, high hydrogen capacity, and favorable hydrogen absorption/desorption characteristics. However, practical application was limited by activation challenges and sensitivity to environmental poisoning.
Yuehai Li +8 more
wiley +1 more source