No abstract

Electrochemical reduction of carbon dioxide (CO2) to carbon monoxide (CO) has attracted increasing attention, because this method provides a new route for CO2 recycling utilization. As CO2 is chemically inert, this reaction requires a high over‐potential. Therefore, it is highly desirable to https://www.baidu.com/link?url=7sgOGZK4RdeP0YlNnWY50FDJ-B6Gu8Iuq8iTl2YcoqyXLYhk-sgGOP9a4kAInk5_Lilex2h9rYXC7iIGJ5gTPCNMlcGx4_GKhidbnPgmlJe&wd=&eqid=bd238ea30000d31a000000045a445227 an electrocatalyst to accelerate this reaction. In the present work, we have investigated numerous imidazolium ionic liquids (ILs) with the aim of looking for a low‐cost homogeneous catalyst with high efficiency. By comparison, 1‐butyl‐3‐methylimidazolium chloride ([Bmim][Cl]) has been selected as the most cost‐effective. To further reduce the cost of [Bmim][Cl], we added [Bmim][Cl] into propylene carbonate(PC)/tetrabutylammonium perchlorate (Bu4NClO4), and used it as the electrocatalyst. Our experimental results show that [Bmim][Cl] has a high catalytic effect for CO2 reduction. The catalytic mechanism of [Bmim][Cl] has been discussed based on electrochemical impedance spectroscopy. It is explained as follows: CO2 was first reduced to the high‐energy CO2.− radical through a one‐electron transfer. The generated CO2.− radical further reacts with [Bmim]+, resulting in the formation of a complex [CO2−Bmim]. Thus, the activation energy of CO2 reduction has been reduced.

No abstract

Electrochemical reduction of carbon dioxide (CO 2 ) to carbon monoxide (CO) has been widely studied in a membrane electrolysis cell. In the cell, a proton exchange membrane has been used as diaphragm to separate the catholyte from the anolyte. However, owing to the high cost of the proton exchange membrane, the practical utilization of the cell has been limited. In present work, we propose a non-membrane electrolysis cell for CO 2 reduction to CO. In this cell, tetrabutylammonium perchlorate (Bu 4 NClO 4 )/propylene carbonate (PC) solution is used as the catholyte, H 2 SO 4 aqueous solution is used as the anolyte. Owing to the hydrophobic nature of Bu 4 NClO 4 /PC, a liquid-liquid interface exists between the catholyte and the anolyte. Thus, electrochemical reduction of CO 2 is carried out in organic media, while H 2 O electro-oxidation is carried out in aqueous solution. Such designed cell has three important advantages over than the membrane electrolysis cell: 1) Owing to the elimination of membrane, the cost of the electrolysis cell is reduced; 2) Because the cell voltage is lowered, the energy efficiency for CO formation is increased; 3) H 2 O generated from CO 2 reduction can transport into the aqueous anolyte without obstacle, the removal of H 2 O from the catholyte is avoided.

With low cost and high safety, zinc metal anodes shine brilliantly in aqueous energy storage batteries. However, the devilish growth of dendrites, high reactivity with water molecules, and undesirable side effects hinder their further application. Here, liquid gallium coverage is subtly introduced on the surface of a commercial zinc foil by a simple scraper process aimed at achieving a dendrite free and excellently reversible zinc anode. Practical interfacial engineering inhibits zinc dendrite formation and mitigates hydrogen evolution and side reactions. In addition, thanks to the liquid metal, the wetting behavior of the electrode/electrolyte interface is significantly optimized. Meanwhile, the fluidity of Ga facilitates the construction of locally homogeneous electric fields and ionic flux. As a result, the prepared Zn@Ga anodes exhibit high reversibility, stable cycle life, and outstanding rate capability. Paired with a manganese dioxide cathode, the Zn@Ga||MnO2 full battery achieves an excellent specific capacity (259.9 mAh g–1) and a consistently long cycle life (capacity retention of 89% after 500 cycles). This study brings a novel perspective to realizing high-performance Zn anodes without dendrites.