搜索到4339篇“ CHEMISORPTION“的相关文章
Lead chemisorption:Paving the last step for industrial perovskite solar cells
2024年
Perovskite solar cells(PSCs)have exhibited impressive performance,achieving a power conversion efficiency(PCE)of 26.1%.However,the water-soluble and toxic nature of lead(Pb)in PSCs hinders their industrialization.Pb chemisorption has emerged as a promising approach to address this issue to prevent Pb leakage and ensure long-term stability.This perspective provides a comprehensive overview of recent advancements in Pb chemisorption in PSCs and discusses the prospects for future developments and challenges in this field.
Pengfei WuJin Hyuck HeoFei Zhang
关键词:PEROVSKITECHEMISORPTION
化学吸附法在石油炼制与化工催化剂研究中的应用
2024年
化学吸附法是一类重要的物化表征手段,在催化剂表征中应用广泛。通过改变探针分子和检测方式,化学吸附法能够提供包括但不限于催化剂表面酸性中心种类和数量、催化剂中金属氧化物物种信息、多组分金属氧化物及金属氧化物与载体之间相互作用、负载型催化剂金属分散度等信息。介绍了氨气程序升温脱附(NH_(3)-TPD)、H_(2)程序升温还原(H_(2)-TPR)、静态化学吸附法、CO脉冲吸附、氢氧滴定法等化学吸附方法的测试原理,总结对比了各方法的优缺点及适用范围,详述了这些方法在表征石油炼制与化工催化剂性质方面的应用案例,最后对方法的优化和未来发展方向进行了展望,以期为更先进的化学吸附方法的开发与其在石油炼制与化工催化剂性质表征方面的应用提供思路。
赵文慧袁蕙卢立军邱丽美王卅徐广通
关键词:化学吸附NH3-TPD
Efficient Polytelluride Anchoring for Ultralong-Life Potassium Storage: Combined Physical Barrier and Chemisorption in Nanogrid-in-Nanofiber
2024年
Metal tellurides(MTes) are highly attractive as promising anodes for high-performance potassium-ion batteries. The capacity attenuation of most reported MTe anodes is attributed to their poor electrical conductivity and large volume variation. The evolution mechanisms, dissolution properties, and corresponding manipulation strategies of intermediates(K-polytellurides, K-pTe_(x)) are rarely mentioned. Herein,we propose a novel structural engineering strategy to confine ultrafine CoTe_(2) nanodots in hierarchical nanogrid-in-nanofiber carbon substrates(CoTe_(2)@NC@NSPCNFs) for smooth immobilization of K-pTe_(x) and highly reversible conversion of CoTe_(2) by manipulating the intense electrochemical reaction process. Various in situ/ex situ techniques and density functional theory calculations have been performed to clarify the formation, transformation, and dissolution of K-pTe_(x)(K_(5)Te_(3) and K_(2)Te), as well as verifying the robust physical barrier and the strong chemisorption of K_(5)Te_(3) and K_(2)Te on S, N co-doped dual-type carbon substrates. Additionally, the hierarchical nanogrid-in-nanofiber nanostructure increases the chemical anchoring sites for K-pTe_(x), provides sufficient volume buffer space, and constructs highly interconnected conductive microcircuits, further propelling the battery reaction to new heights(3500 cycles at 2.0 A g^(-1)). Furthermore, the full cells further demonstrate the potential for practical applications. This work provides new insights into manipulating K-pTe_(x) in the design of ultralong-cycling MTe anodes for advanced PIBs.
Qinghua LiDandan YuJian PengWei ZhangJianlian HuangZhixin LiangJunling WangZeyu LinShiyun XiongJiazhao WangShaoming Huang
钙或钾催化锯齿形边缘炭化学吸附二氧化碳的波函数和分子反应性研究
2024年
本研究采用波函数理论和密度泛函反应性理论,系统地研究掺杂了钙(Ca)或钾(K)的锯齿形边缘炭模型的分子反应性以及对化学吸附二氧化碳(CO2)性能的影响。通过比较不同金属负载炭模型的电负性、亲电性和亲核性,得出了CO2在其炭模型上的化学吸附是亲电反应的结论。并进一步分析了最低未占据分子轨道(LUMO)和最高已占据分子轨道(HOMO),表明碱土金属Ca或碱金属K的掺杂改变了焦炭的电荷分布特性。通过研究电子局域化函数填色图和电子密度差,发现负载金属边缘充满更多的孤对电子,并且该边缘区域电子的局域化程度更高,因此更容易受到亲电攻击,易作为吸附位点考虑。借助双描述符、HOMO和LUMO的轨道成分的研究,预测了在掺杂了Ca或K的炭模型吸附CO2的位点。此外,计算了不同模型下化学吸附CO2释放的能量,最终吸附CO2的热力学结果与波函数理论和密度泛函反应性理论的预测结果一致。
王波詹世强张杰
关键词:二氧化碳密度泛函理论
Chemisorption solid materials for hydrogen storage near ambient temperature:A review被引量:1
2023年
Solid chemisorption technologies for hydrogen storage,especially high-efficiency hydrogen storage of fuel cells in near ambient temperature zone defined from−20 to 100℃,have a great application potential for realizing the global goal of carbon dioxide emission reduction and vision of carbon neutrality.However,there are several challenges to be solved at near ambient temperature,i.e.,unclear hydrogen storage mechanism,low sorption capacity,poor sorption kinetics,and complicated synthetic procedures.In this review,the characteristics and modification methods of chemisorption hydrogen storage materials at near ambient temperature are discussed.The interaction between hydrogen and materials is analyzed,including the microscopic,thermodynamic,and mechanical properties.Based on the classification of hydrogen storage metals,the operation temperature zone and temperature shifting methods are discussed.A series of modification and reprocessing methods are summarized,including preparation,synthesis,simulation,and experimental analysis.Finally,perspectives on advanced solid chemisorption materials promising for efficient and scalable hydrogen storage systems are provided.
Yiheng ZHANGShaofei WULiwei WANGXuefeng ZHANG
关键词:CHEMISORPTION
Eliminating nitrogen chemisorption barrier with single-atom supported yttrium cluster via electronic promoting effect for highly efficient ammonia synthesis
2023年
Nitrogen chemisorption is a prerequisite for efficient ammonia synthesis under ambient conditions,but promoting this process remains a significant challenge.Here,by loading yttrium clusters onto a single-atom support,an electronic promoting effect is triggered to successfully eliminate the nitrogen chemisorption barrier and achieve highly efficient ammonia synthesis.Density functional theory calculations reveal that yttrium clusters with abundant electron orbitals can provide considerable electrons and greatly promote electron backdonation to the N2 antibonding orbitals,making the chemisorption process exothermic.Moreover,according to the“hot atom”mechanism,the energy released during exothermic N2 chemisorption would benefit subsequent N2 cleavage and hydrogenation,thereby dramatically reducing the energy barrier of the overall process.As expected,the proof-of-concept catalyst achieves a prominent NH3 yield rate of 48.1μg·h^(−1)·mg^(−1)at−0.2 V versus the reversible hydrogen electrode,with a Faradaic efficiency of up to 69.7%.This strategy overcomes one of the most serious obstacles for electrochemical ammonia synthesis,and provides a promising method for the development of catalysts with high catalytic activity and selectivity.
Yuzhuo JiangMengfan WangSisi LiuLifang ZhangSiyi QianYufeng CaoYu ChengTao QianChenglin Yan
基底化学吸附对石墨烯机械裁剪性能的影响机制
2023年
机械裁剪法是简单高效制备石墨烯纳米带的加工方法,目前对基底化学吸附如何影响石墨烯机械裁剪行为的认识尚有不足。为探究基底化学吸附对石墨烯机械裁剪性能的影响机制,基于ReaxFF反应力场和Verlet算法,采用反应分子动力学方法对Ni、Pt、Cu金属基底上的石墨烯机械裁剪行为展开研究,根据纳米压痕和机械裁剪中探针与石墨烯(C_(T)-C_(G))、石墨烯层内(C_(G)-C_(G))、石墨烯与基底(C_(G)-M)间键合数量和键合强度的变化规律,分析基底化学吸附对键合性能和石墨烯机械裁剪行为的影响。结果表明:Ni、Pt、Cu基底对石墨烯的化学吸附能力依次减弱,强化学吸附作用增大了C_(G)-M键合强度,促进了C_(T)-C_(G)键合,削弱了C_(G)-C_(G)键合强度,降低了石墨烯的抗破损强度,Ni、Pt、Cu基底上的石墨烯抗破损强度分别为110.19、121.71、176.53 GPa。强化学吸附使石墨烯发生了大面积撕裂破损,弱化学吸附使石墨烯仅发生了部分碳链和碳原子的剥离。强化学吸附基底提高了石墨烯的机械裁剪效率,减小了机械裁剪深度,降低了探针下压载荷,提高了探针对石墨烯的摩擦力,提高了石墨烯的机械裁剪性能。基于反应分子动力学方法可深入探究基底化学吸附对石墨烯机械裁剪性能的影响规律及内在机理,研究结果可为不同化学吸附基底条件下高效、高精度石墨烯纳米带的机械裁剪提供理论依据。
冉迪郑鹏苑泽伟王宁
关键词:化学吸附石墨烯分子动力学
N_(2)O脉冲吸附法测定镍基催化剂分散度
2023年
文章介绍了一种通过N_(2)O脉冲吸附测定镍基催化剂分散度的实验方法及相应实验设备的改装方法,并探讨了吸附温度对分散度测定的影响。相比于其他分散度测量方法,该方法反应装置简易,操作简单快捷,实验结果可靠性高。该实验结合化工专业的实践教学要求与学科前沿方向,有助于培养学生的科研素养、拓展学生的专业视野,具有引入化工学科实验教学的可行性。
黄瑜慧包梦瑶王震孙莉费妮娜朱明辉
关键词:分散度
具有高效化学吸附、增强的载流子分离及抗光腐蚀能力的CdS/COF核壳结构纳米棒用于光催化还原铀
2023年
基于半导体光催化剂将可溶的六价铀(U(Ⅵ))还原为不可溶的四价铀(U(Ⅳ))是一种简便、环保、高效的铀提取方法.实现该技术的关键是开发在无牺牲剂情况下对于光催化还原铀具有高活性和稳定性的催化剂.本文报道了一种新型CdS/COF核壳结构光催化剂(CdS@COF-10),该催化剂具有高效的化学吸附、增强的载流子分离和抗光腐蚀能力,无需额外的牺牲剂即可用于高效的光催化还原铀.COF壳层不仅为U(Ⅵ)提供了化学吸附位点,降低了U(Ⅵ)还原的活化能,而且在与CdS核的界面处形成了内建电场,促进了载流子的分离.更重要的是,具有适当COF壳含量的CdS-COF-10在结晶度、界面接触完整性、CdS核的光吸收和U(Ⅵ)化学吸附位点数量之间取得了平衡,获得了最高的载流子分离效率和光催化还原铀性能.
喻开富何攀何宁宁李小锋董昌雪蒋博邹莹迪裴响李阳马利建
Electronic structure factors and the importance of adsorbate effects in chemisorption on surface alloys
2022年
The chemisorption energy is an integral aspect of surface chemistry,central to numerous fields such as catalysis,corrosion,and nanotechnology.Electronic-structure-based methods such as the Newns-Anderson model are therefore of great importance in guiding the engineering of material surfaces with optimal properties.However,existing methods are inadequate for interpreting complex,multi-metallic systems.Herein,we introduce a physics-based chemisorption model for alloyed transition metal surfaces employing primarily metal d-band properties that accounts for perturbations in both the substrate and adsorbate electronic states upon interaction.Importantly,we show that adsorbate-induced changes in the adsorption site interact with its chemical environment leading to a second-order response in chemisorption energy with the d-filling of the neighboring atoms.We demonstrate the robustness of the model on a wide range of transition metal alloys with O,N,CH,and Li adsorbates yielding a mean absolute error of 0.13 eV versus density functional theory reference chemisorption energies.
Shikha SainiJoakim Halldin StenlidFrank Abild-Pedersen
关键词:ALLOYSCORROSIONCHEMISORPTION

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李明愉
作品数:78被引量:319H指数:10
供职机构:北京理工大学机电学院
研究主题:离子交换纤维 螯合纤维 叠氮化物 离子交换剂 吸附热力学
王文庆
作品数:3被引量:3H指数:1
供职机构:北京理工大学
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曾庆轩
作品数:200被引量:1,084H指数:17
供职机构:北京理工大学
研究主题:离子交换纤维 数值模拟 聚丙烯纤维 聚丙烯 螯合纤维
王华
作品数:1被引量:0H指数:0
供职机构:中国工程物理研究院
研究主题:GEOMETRIC DENSITY_FUNCTIONAL_THEORY UN RELAXATION O2