冶金生产过程危险识别及评价技术

生产过程危险识别及评价技术涉及人身安全和设备安全,是关系到国民经济正常运行和社会稳定的重要工作,其作用不是对发生的事故事后进行总结分析,而是在发生事故前就能识别,并评价其危害程度,可为管理决策层制定防治事故的对策提供依据,从而预先采取措施,防止事故的发生。     

Ultrathin Iron‐Cobalt Oxide Nanosheets with Abundant Oxygen Vacancies for the Oxygen Evolution Reaction

Electrochemical water splitting is a promising method for storing light/electrical energy in the form of H₂ fuel; however, it is limited by the sluggish anodic oxygen evolution reaction (OER). To improve the accessibility of H₂ production, it is necessary to develop an efficient OER catalyst with large surface area, abundant active sites, and good stability, through a low‐cost fabrication route. Herein, a facile solution reduction method using NaBH₄ as a reductant is developed to prepare iron‐cobalt oxide nanosheets (Fe_x Co_y ‐ONSs) with a large specific surface area (up to 261.1 m² g^?1), ultrathin thickness (1.2 nm), and, importantly, abundant oxygen vacancies. The mass activity of Fe₁Co₁‐ONS measured at an overpotential of 350 mV reaches up to 54.9 A g^?1, while its Tafel slope is 36.8 mV dec^?1; both of which are superior to those of commercial RuO₂, crystalline Fe₁Co₁‐ONP, and most reported OER catalysts. The excellent OER catalytic activity of Fe₁Co₁‐ONS can be attributed to its specific structure, e.g., ultrathin nanosheets that could facilitate mass diffusion/transport of OH^? ions and provide more active sites for OER catalysis, and oxygen vacancies that could improve electronic conductivity and facilitate adsorption of H₂O onto nearby Co³⁺ sites.     

双膜法水处理工艺在冶金污水回用系统的应用

双膜法（超滤+反渗透）水处理工艺具有出水水质好、易于实现自控、占地面积小、节水环保等特点；文章重点介绍了双膜法工艺在邯钢污水回用系统中的应用情况。     

冶金型空分设备的流程选择

简要介绍了一般冶金型大中型空分设备常用的三种流程型式,同时从常规空分设备的考核方面对上述流程的各自特点进行详细比较和内在分析,指出了三种流程的优缺点及其所适用的产品规格。     

Linear Conjugated Coordination Polymers for Electrocatalytic Oxygen Evolution Reaction

Conjugated coordination polymers (CCPs) have attracted extensive attention for various applications related to energy storage and conversion in the past few years, despite that there are many CCPs with unclear chemical states and structures. Here, linear CCPs (LCCPs), with metal–O₄ active sites grown on carbon paper (CP) for oxygen evolution reaction (OER), are presented. The LCCPs with high crystallinity and simple structures exhibit the order of electrocatalytic activity of Co–O₄ > Ni–O₄ > Fe–O₄ in terms of the metal–O₄ centers. The Co-based LCCP shows higher OER performance (263 mV at 10 mA cm⁻²) and better durability (90 h at 30 mA cm⁻²) than commercial IrO₂/CP. The structures and chemical states of LCCPs are carefully investigated, and density functional theory is used to reveal the mechanism of OER at the central metal site. This investigation into LCCPs provides new sights for a better understanding of CCPs and expands the applications of LCCPs with metal–O₄ sites.     

Formation of Branched Ruthenium Nanoparticles for Improved Electrocatalysis of Oxygen Evolution Reaction

Branched nanoparticles are one of the most promising nanoparticle catalysts as their branch sizes and surfaces can be tuned to enable both high activity and stability. Understanding how the crystallinity and surface facets of branched nanoparticles affect their catalytic performance is vital for further catalyst development. In this work, a synthesis is developed to form highly branched ruthenium (Ru) nanoparticles with control of crystallinity. It is shown that faceted Ru branched nanoparticles have improved stability and activity in the oxygen evolution reaction (OER) compared with polycrystalline Ru nanoparticles. This work achieves a low 180 mV overpotential at 10 mA cm^?2 for hours, demonstrating that record‐high stability for Ru nanocrystals can be achieved while retaining high activity for OER. The superior electrocatalytic performance of faceted Ru branched nanoparticles is ascribed to the lower Ru dissolution rate under OER conditions due to low‐index facets on the branch surfaces.     

二维过渡金属硫属化合物氧还原反应催化剂的研究进展

氧还原(ORR)反应是燃料电池等清洁能源阴极的关键反应, 其反应动力学复杂, 阴极需使用Pt等贵金属催化剂。然而Pt价格昂贵, 且载体炭黑在高电位环境下稳定性欠佳, 导致电池部件成本高且寿命短。二维过渡金属硫属化合物(2D TMDs)具有高比表面积与可调节的电学性能, 且稳定性强, 有望在维持活性的同时提高燃料电池阴极的耐久性。本文梳理了近年来2D TMDs在ORR催化剂领域的最新研究进展: 首先概述了2D TMDs的结构、性质及ORR反应机理; 其次分析了调控2D TMDs的ORR性能策略, 包括异质元素掺杂、相转变、缺陷工程与应力工程等, 介绍了2D TMDs基异质结构对ORR性能的提升作用; 最后, 针对该领域目前存在的挑战进行展望与总结。     

2D Electron Gas and Oxygen Vacancy Induced High Oxygen Evolution Performances for Advanced Co3O4/CeO2 Nanohybrids

The rational design of atomic‐scale interfaces in multiphase nanohybrids is an alluring and challenging approach to develop advanced electrocatalysts. Herein, through the selection of two different metal oxides with particular intrinsic features, advanced Co₃O₄/CeO₂ nanohybrids (NHs) with CeO₂ nanocubes anchored on Co₃O₄ nanosheets are developed, which show not only high oxygen vacancy concentration but also remarkable 2D electron gas (2DEG) behavior with ≈0.79 ± 0.1 excess e^?/u.c. on the Ce³⁺ sites at the Co₃O₄–CeO₂ interface. Such a 2DEG transport channel leads to a high carrier density of 3.8 × 10¹⁴ cm^?2 and good conductivity. Consequently, the Co₃O₄/CeO₂ NHs demonstrate dramatically enhanced oxygen evolution reaction (OER) performances with a low overpotential of 270 mV at 10 mA cm^?2 and a high turnover frequency of 0.25 s^?1 when compared to those of pure Co₃O₄ and CeO₂ counterparts, outperforming commercial IrO₂ and some recently reported representative OER catalysts. These results demonstrate the validity of tailoring the electrocatalytic properties of metal oxides by 2DEG engineering, offering a step forward in the design of advanced hybrid nanostructures.     

Fabrication of Hollow CoP/TiOx Heterostructures for Enhanced Oxygen Evolution Reaction

Transition‐metal phosphides have flourished as promising candidates for oxygen evolution reaction (OER) electrocatalysts. Herein, it is demonstrated that the electrocatalytic OER performance of CoP can be greatly improved by constructing a hybrid CoP/TiO_x heterostructure. The CoP/TiO_x heterostructure is fabricated using metal–organic framework nanocrystals as templates, which leads to unique hollow structures and uniformly distributed CoP nanoparticles on TiO_x. The strong interactions between CoP and TiO_x in the CoP/TiO_x heterostructure and the conductive nature of TiO_x with Ti³⁺ sites endow the CoP–TiO_x hybrid material with high OER activity comparable to the state‐of‐the‐art IrO₂ or RuO₂ OER electrocatalysts. In combination with theoretical calculations, this work reveals that the formation of CoP/TiO_x heterostructure can generate a pathway for facile electron transport and optimize the water adsorption energy, thus promoting the OER electrocatalysis.     

Ferrocene‐Incorporated Cobalt Sulfide Nanoarchitecture for Superior Oxygen Evolution Reaction

Here, ferrocene(Fc)‐incorporated cobalt sulfide (Co_xS_y) nanostructures directly grown on carbon nanotube (CNT) or carbon fiber (CF) networks for electrochemical oxygen evolution reaction (OER) using a facile one‐step solvothermal method are reported. The strong synergistic interaction between Fc‐Co_xS_y nanostructures and electrically conductive CNTs results in the superior electrocatalytic activity with a very small overpotential of ≈304 mV at 10 mA cm^?2 and a low Tafel slope of 54.2 mV dec^?1 in 1 m KOH electrolyte. Furthermore, the Fc‐incorporated Co_xS_y (FCoS) nanostructures are directly grown on the acid pretreated carbon fiber (ACF), and the resulting fabricated electrode delivers excellent OER performance with a low overpotential of ≈315 mV at 10 mA cm^?2. Such superior OER catalytic activity can be attributed to 3D Fc‐Co_xS_y nanoarchitectures that consist of a high concentration of vertical nanosheets with uniform distribution of nanoparticles that afford a large number of active surface areas and edge sites. Besides, the tight contact interface between ACF substrate and Fc‐Co_xS_y nanostructures could effectively facilitate the electron transfer rate in the OER. This study provides valuable insights for the rational design of energy storage and conversion materials by the incorporation of other transition metal into metal sulfide/oxide nanostructures utilizing metallocene.     

Defect-Engineered Mesoporous Undoped Carbon Nanoribbons for Benchmark Oxygen Reduction Reaction

For large-scale fuel cell applications, it is significant to replace expensive Pt-based oxygen reduction reaction (ORR) electrocatalysts with nonprecious metal- or metal-free carbon-based catalysts with high activity. However, it is still challenging to deeply understand the role of intrinsic defects and the origin of ORR activity in pure nanocarbon. Therefore, a novel self-assembly and a pyrolysis strategy to fabricate defect-rich mesoporous carbon nanoribbons are presented. Due to the effective regulation of nanoarchitecture, a vast number of defective catalytic sites (edge defects and holes) are exposed, which thereby enhances the electron transfer kinetics and catalytic activity. Such undoped nanoribbons display a large half-wave potential of 0.837 V, excellent long-term stability, and exceptional methanol tolerance, surpassing the most undoped ORR catalysts and the commercial Pt/C (20 wt.%) catalyst. Structural characterizations and density functional theory (DFT) calculations confirm that the zigzag edge defects and the armchair pentagon at the hole defect are responsible for outstanding ORR performance.     

化学链制氧技术铜基氧载体的性能研究

在STA409PC热重分析仪上对Cu/Si氧载体的脱氧-吸氧性能加以研究, 并利用BET、SEM和XRD对所制备氧载体的比表面积、表面形貌和物相组成进行分析。结果表明, 在N₂氛围中, 当温度高于850℃时Cu/Si氧载体脱氧反应进入快速反应阶段; 氧载体在空气氛围中再生的快速反应温度高于400℃; 氧载体脱氧和吸氧的反应速率随颗粒直径的减小及气体流量的增大, 而增大但变化不明显, 而随反应温度的升高, 氧载体脱氧和吸氧反应速率都会急剧增大; 23次循环实验中, 氧载体脱氧-吸氧性能稳定, 经循环之后的氧载体, 颗粒表面变得光滑, 空隙率增加, 但机械强度降低。物相分析结果表明氧载体脱氧后的成分主要有Cu₂O和SiO₂, 吸氧后的成分主要有CuO和SiO₂, 氧载体的制备方法和循环性能有很好的稳定性和适应性。     

金属掺杂聚吡咯碳化物PPY-M的制备及其氧还原反应电催化活性

在Fe³⁺或Co²⁺存在下进行吡咯的聚合反应, 得到金属离子掺杂的聚吡咯, 并在N₂气氛下700℃碳化, 再将该碳化产物在900℃焙烧得到含有不同金属的复合催化剂PPY-M(M为不同的金属)。采用SEM、XRD等对催化剂的结构进行了表征。通过循环伏安和线性电位扫描等电化学手段, 研究了催化剂对氧还原(ORR)的电催化活性及其稳定性。结果表明, 掺杂金属钴的催化剂的活性最好, 在酸性溶液中ORR的起始电位达到0.54 V(vs SCE),电流密度为7.5 mA/mg@-0.3 V(vs SCE); 在碱性溶液中ORR的起始电位为-0.11 V(vs SCE),电流密度为5.7 mA/mg@-0.8 V。Fe或Co掺杂的聚吡咯碳化物对ORR具有较强的电催化活性, 而且制备过程简单、成本低, 有较重要的研究意义。     

氧还原反应的量子化学模型及其催化活性指示符研究进展

氧还原反应是质子交换膜燃料电池的重要电化学过程.从分子(原子)水平研究氧还原反应对质子交换膜燃料电池催化剂开发具有重要的指导意义.因此,用于分子(原子)水平研究的量子化学方法被引入氧还原反应研究.简要综述了几种常用的氧还原反应量子化学模型及其催化活性指示符,并分析比较了这几种量子化学模型的适用范围.     

冶金法制备太阳能级多晶硅新工艺原理及研究进展

随着光伏市场需求不断增加,能满足光伏电池技术经济指标要求的硅材料出现严重短缺,冶金法制备太阳能级多晶硅新工艺技术由于其能耗低、成本低,越来越受到国内外的广泛重视,成为研究开发的热点.综述了近年来国内外有关冶金法提纯冶金级硅至太阳能级硅的各种工艺路线的原理及成果,并进行了比较分析,展望了其应用前景.