Recent advances in one-dimensional nanostructures for energy electrocatalysis

Catalysts play decisive roles in determining the energy conversion efficiencies of energy devices. Up to now, various types of nanostructured materials have been studied as advanced electrocatalysts. This review highlights the application of one-dimensional (1D) metal electrocatalysts in energy conversion, focusing on two important reaction systems—direct methanol fuel cells and water splitting. In this review, we first give a broad introduction of electrochemical energy conversion. In the second section, we summarize the recent significant advances in the area of 1D metal nanostructured electrocatalysts for the electrochemical reactions involved in fuel cells and water splitting systems, including the oxygen reduction reaction, methanol oxidation reaction, hydrogen evolution reaction, and oxygen evolution reaction. Finally, based on the current studies on 1D nanostructures for energy electrocatalysis, we present a brief outlook on the research trend in 1D nanoelectrocatalysts for the two clean electrochemical energy conversion systems mentioned above.     

铑催化合成气转化为乙醇反应中甲酰基中间体的化学捕获

本文采用化学捕获法对铑基催化剂上合成气转化反应中的甲酰基中间体进行了化学捕获,在CO+2D_2反应后,用CH_3I进行的化学捕获反应中生成了CH_3CHO、CH_3CDO两种形式的乙醛;补充的Ar吹扫实验显示DCO的甲基化反应对生成的CH_3CDO有重要贡献。因此,甲酰基的确是合成气反应中的C_1含氧中间体。根据这一结果,初步探讨了合成气反应中CH_x物种的生成途径。     

锰球制备条件对氮化反应的影响

利用自制的密闭氮化系统研究不同制备条件的锰球的氮化反应.考察锰粉粒度、成球压力和黏结剂添加量对氮化反应的影响,并测量锰球氮化过程中实时增重和温度曲线.实验结果表明:锰粉粒度由16 ～40目变成60 ～ 80目时,球心温度到达峰值的时间由164 s缩短为101s,球心最大温升由147℃增至233℃,氮化1h的转化率由90.81％增至93.64％;成球压力由266 MPa增至443 MPa,球心峰值温度将提前89 s到达,球心最大温升将提高22℃,氮化1h的转化率由91.59％增至94.92％;黏结剂添加量由1 g增至3 g,氮化1h的转化率由92.90％降至89.80％;正态对数分布的概率密度函数可用来近似拟合转化速率与时间的关系.     

(n‐Bu2Sn)2O(CO3): An active,robust and recyclable organotin(IV) for the direct synthesis of linear organic carbonates from carbon dioxide and alcohols

Organotin(IV) compounds are known to promote the direct synthesis of organic carbonates from carbon dioxide and alcohols. In the past, structural studies have highlighted that the carbonato moiety is a recurring ligand of tin species collected during CO₂ pressurized reactions. In a mimetic approach and in order to achieve an available and recyclable precursor, the title compound (n ‐Bu₂Sn)₂O(CO₃) ( 1 ) was prepared in a single step by reacting commercial di‐n ‐butyltin dichloride with an aqueous solution of sodium carbonate. Compound 1 was characterized using infrared spectroscopy and thermogravimetric and elemental analyses. Multinuclear NMR investigations in solution were also conducted. Compound 1 was then evaluated for the direct carbonation of alcohols (methanol, ethanol, n ‐butanol and isopropanol) under CO₂ pressure. Recycling experiments were performed showing the efficient reuse of 1 without loss of activity. Furthermore, the infrared fingerprint of 1 was preserved even after several runs demonstrating a good stability. The effects of pressure and of reaction time on dimethyl carbonate formation were also studied.     

基于论域和量值二类错误逻辑变量求解的识别对象状态转化及其决策应用研究

研究了空间事物特征为确定常量的条件下,论域和量值参数为变量且未知时,错误识别对象状态的转化.研究发现,当对象识别状态的论域和量值都为Ⅱ类时,可以采用错误矩阵一类4集合方程A_s∨X_(qg)■B_g构建二元置换变换错误矩阵集合方程,将错误的对象识别状态转化为应该状态.最后,通过生产决策的实例说明其实际决策应用价值.     

钧瓷创意设计教学成果转化的机制与途径研究

近年来高校文化创意产业发展在高校的非遗文创课程设计教学体系中的比重有所增加,从创意产品成果转化角度探索钧瓷创意设计教学实践,开展多种形式的创新创业课程,以此提升钧瓷创意设计成果转化的教改效果。同时也是创意设计教学成果转化各环节措施的探索,实现钧瓷创意设计教学成果转化的人才培养机制与企业创新的深度融合。     

Azo-Functionalized Zirconium-Based Metal−Organic Polyhedron as an Efficient Catalyst for CO2 Fixation with Epoxides

Chemical fixation of CO₂ as C1 source at ambient temperature and low pressure is an energy-saving way to make use of the green-house gas, but it still remains a challenge since efficient catalyst with high catalytic active sites is required. Here, a novel monoclinic azo-functionalized Zr-based metal−organic polyhedron (Zr-AZDA) has been prepared and applied in CO₂ fixation with epoxides. The inherent azo groups not only endow Zr-AZDA with good solubilization, but also act as basic sites to enrich CO₂ showing efficient synergistic catalysis as confirmed by TPD-CO₂ analysis. XPS results demonstrate that the Zr active sites in Zr-AZDA possess suitable Lewis acidity, which satisfies both substrates activation and products desorption. DFT calculation indicates the energy barrier of the rate-determining step in CO₂ cycloaddition could be reduced remarkably (by ca. 60.9 %) in the presence of Zr-AZDA, which may rationalize the mild and efficient reaction condition employed (80 °C and 1 atm of CO₂). The work provides an effective multi-functional cooperative method for improvement of CO₂ cycloaddition.     

Electrochemical On‐line ICP‐MS in Electrocatalysis Research

Electrocatalyst degradation due to dissolution is one of the major challenges in electrochemical energy conversion technologies such as fuel cells and electrolysers. While tendencies towards dissolution can be grasped considering available thermodynamic data, the kinetics of material's stability in real conditions is still difficult to predict and have to be measured experimentally, ideally in‐situ and/or on‐line. On‐line inductively coupled plasma mass spectrometry (ICP‐MS) is a technique developed recently to address exactly this issue. It allows time‐ and potential‐resolved analysis of dissolution products in the electrolyte during the reaction under dynamic conditions. In this work, applications of on‐line ICP‐MS techniques in studies embracing dissolution of catalysts for oxygen reduction (ORR) and evolution (OER) as well as hydrogen oxidation (HOR) and evolution (HER) reactions are reviewed.     

YA7232B磨床逆变器片上系统的研究与设计

蜗杆砂轮磨齿机YA7232B采用交流同步电机开环调速系统,系统的动态性能较低.采用磁场定向控制FOC算法和反电势锁相环位置估算器(BEMF PLL),重构无传感器交流同步电机的速度和角度参数,设计逆变调速片上系统(So C).经电气系统的技术改造、调试、验证和检测,结果表明采用的设计方法提高了磨齿机的齿轮加工精度和综合电气性能.