Enhanced Carbon Monoxide Electroreduction to >1 A cm−2 C2+ Products Using Copper Catalysts Dispersed on MgAl Layered Double Hydroxide Nanosheet House-of-Cards Scaffolds

Cu catalysts are most apt for reducing CO₍₂₎ to multi-carbon products in aqueous electrolytes. To enhance the product yield, we can increase the overpotential and the catalyst mass loading. However, these approaches can cause inadequate mass transport of CO₍₂₎ to the catalytic sites, which will then lead to H₂ evolution dominating the product selectivity. Herein, we use a MgAl LDH nanosheet ‘house-of-cards’ scaffold to disperse CuO-derived Cu (OD-Cu). With this support-catalyst design, at −0.7 V_RHE, CO could be reduced to C₂₊ products with a current density (j_C2+) of −1251 mA cm⁻². This is 14× that of the j_C2+ shown by unsupported OD-Cu. The current densities of C₂₊ alcohols and C₂H₄ were also high at −369 and −816 mA cm⁻² respectively. We propose that the porosity of the LDH nanosheet scaffold enhances CO diffusion through the Cu sites. The CO reduction rate can thus be increased, while minimizing H₂ evolution, even when high catalyst loadings and large overpotentials are used.     

三角波电流激励示波计时电位法的研究

推导了三角波电流激励波计时的电位方程，讨论了电流幅值、频率和去极剂离子对示波图的影响，并对双电层微分电容的作用进行了详细的讨论，给出了示波端点电位的表达式和理论议程的适用条件。     

自掺杂La1-δMn1-δO3化合物的晶体结构和巨磁电阻效应

采用溶胶-凝胶工艺制备了La1-δMn1-δO3化合物.研究了烧结条件的改变对材料的结构、磁性、导电性、磁电阻效应的影响.首次发现La1-δMn1-δO3化合物的电阻-温度曲线的双峰现象.     

Co0−Coδ+ Interface Double-Site-Mediated C−C Coupling for the Photothermal Conversion of CO2 into Light Olefins

Solar-driven CO₂ hydrogenation into multi-carbon products is a highly desirable, but challenging reaction. The bottleneck of this reaction lies in the C−C coupling of C₁ intermediates. Herein, we construct the C−C coupling centre for C₁ intermediates via the in situ formation of Co⁰−Co^δ+ interface double sites on MgAl₂O₄ (Co−CoO_x/MAO). Our experimental and theoretical prediction results confirmed the effective adsorption and activation of CO₂ by the Co⁰ site to produce C₁ intermediates, while the introduction of the electron-deficient state of Co^δ+ can effectively reduce the energy barrier of the key CHCH* intermediates. Consequently, Co−CoO_x/MAO exhibited a high C_2–4 hydrocarbons production rate of 1303 μmol g⁻¹ h⁻¹; the total organic carbon selectivity of C_2–4 hydrocarbons is 62.5 % under light irradiation with a high ratio (≈11) of olefin to paraffin. This study provides a new approach toward the design of photocatalysts used for CO₂ conversion into C₂₊ products.     

苯及苯磺酸基官能化的中孔分子筛的合成及催化应用

近年来 ,通过对介孔分子筛 (如 MCM,HMS,MSU-X)结构及组成的化学“裁剪”,制备具有特定结构和表面性质的催化材料成为该领域的研究热点之一 [1～ 5] .许多文献报道了 MCM-4 1的有机官能化中孔材料的制备技术 [5～ 8] ,并将其应用于有机合成反应 ,取得了较好的结果 [7,8] .其中 MSU-X介孔分子筛结构具有三维排列“Worm-like”孔道特征 ,有利于物料传输 ;相对于 MCM-4 1分子筛在合成方面具有以中性表面活性剂作模板剂且模板剂容易去除等诸多优点[9] .本文采用非离子表面活性剂 C11— 15H2 3— 31(CH2 CH2 O) 9H(AEO9)为模板剂 ,…     

CdTe/CdS@SiO_2@BPEI-CQDs双发射比率荧光探针的构建及在测定生物样品中Cu(Ⅱ)的应用

本文制备了对Cu(Ⅱ)具有选择性识别作用的Cd Te/Cd S@Si O_2@BPEI-CQDs双发射比率荧光探针。基于Cu(Ⅱ)能使探针表面的BPEI-CQDs荧光猝灭的现象,建立了测定Cu(Ⅱ)的比率荧光新方法。在最佳条件下,该方法测定Cu(Ⅱ)的线性范围为0.40~70μmol/L,检测限为0.27μmol/L。建立的方法已被成功用于人体尿液及血浆中Cu(Ⅱ)的测定。     

Preparation and characterization of W/O/W type double emulsion containing PGPR–lecithin mixture as lipophilic surfactant

The objective of this study is to produce double emulsion by combining polyglycerol polyricinoleate (PGPR) with lecithin as lipophilic surfactant. Although lecithin alone produced only oil-in-water type emulsion, the mixture of lecithin and PGPR could produce water-in-oil type emulsion as well. Moreover, different emulsification treatments were applied to study the influence of homogenization methods on the physicochemical characteristics. The obtained double emulsions were compared in terms of stability and droplet size. It was found that the homogenization method influenced the physiochemical characteristics of the double emulsion and the most stable double emulsion with the smallest droplet size was obtained by high-speed homogenization method.