Electrolyte Tailoring for Electrocatalytic Reduction of Stable Molecules

本文概述了惰性小分子电催化还原反应（如二氧化碳还原反应和氮气还原反应）中电解液的组成和作用机制,介绍了相关电解液研究的最新进展,并讨论了电解液调控在揭示反应机理、改善催化性能中的重要作用.Reduction of stable molecules such as CO2 and N2 is important process in electrochemical energy conversion and storage technologies for electrofuels production. However, for the inert nature of CO2/N2 molecule and competitive proton reduction in conventional aqueous electrolytes, selective electrochemical carbon/nitrogen fixation suffers from high overpotential, low reaction rate and low selectivity. While addressing these issues has witnessed substantial advances in electrocatalysts, much less attention has been placed on the electrolytes, which play an important role in regulating the local environment and thus the performance of catalysts under operating conditions. Rational design of electrolytes has received increasing interest to boost the activity and selectivity of stable molecule electrocatalysis. In this review, we overview recent progress in mechanistic understanding and strategies development in tailoring electrolytes for electrocatalytic CO2 and N2 reduction. We highlight the ion effect, local environment, and interface structure of electrocatalysts and electrolytes based on experimental and computational studies on representative examples. Particular discussion is provided on the effect of local pH modulation, electrolyte concentrating, selective ionic adsorption and nonaqueous electrolyte.国家自然科学基金项目(21925503);国家自然科学基金项目(21871149);国家重点研发计划纳米科技专项(2017YFA0206700);中央高校基本科研业务费专项资金项目资助通讯作者:程方益E-mail:[email protected]:CHENGFang-yiE-mail:[email protected]南开大学化学学院,先进能源材料化学教育部重点实验室,新能源转化与存储交叉科学中心,天津 300071Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Renewable Energy Conversion and Storage Center (ReCast), College of Chemistry, Nankai University, Tianjin 300071, Chin

Preparation and Electrochemical Properties of Sn Thin Film as Anode Materials for Lithium-Ion Batteries

应用真空蒸发法在泡沫铜基底上制备锡薄膜负极.XRD、SEM分析表征薄膜的物相结构及其微观形貌,并测试了材料的电化学性能.结果表明,泡沫铜基底的三维结构增强了活性物质与基底的结合力.在同一基底温度下,锡颗粒随蒸发时间延长逐渐增大,电池电化学性能降低;而在同一时间内,升高基底温度,颗粒无明显变化,电池循环寿命有了很大提高.样品A″电池(基底温度:200℃,蒸发时间:0.5 h)经100次充放电循环后比容量仍达407.3 mAh·g-1.Sn thin films as the anode materials of Li-ion batteries were prepared by vacuum-evaporation method on the copper foam substrate.The phase structure,surface morphology and electrochemical property of the as-prepared films were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),and galvanostatic cycling.The results showed that three-dimensional structure of copper foam substrate enhanced the adhesion strength between the active material and the substrate,under the same substrate temperature,the particles became bigger with the increasing of evaporation time,while their electrochemical property decreased;under the same evaporation time,the particles didn′t changed obviously with the increasing of substrate temperature,while their cycle life increased.The battery of sample A″(substrate temperature:200 ℃,evaporation time:0.5 h) maintained a discharge capacity of 407.3 mAh·g-1 after 100 cycles.作者联系地址：南开大学新能源材料化学研究所先进能源材料化学教育部重点实验室;Author's Address: Institute of New Energy and Material Chemistry,Key Laboratory of Advanced Energy Materials Chemistry-Ministry of Education,Nankai University,Tianjin 300071,Chin

Synthesis of Zinc Polyhedral Microspheres and Applications in Alkaline Zn-MnO_(2)Battery

应用加热蒸发高纯锌粉气相传输法,制备锌多面体微球.产物的结构和形貌经XRD、SEM等测试表征,结果表明与该产物为结晶度较好的直径2~3μm的多面体微球.分别以所制锌微球或市售熔融锌作负极,γ-MnO2纳米线为正极,组装AA型碱性锌锰电池.电化学测试表明以锌微球为负极的碱性锌锰电池能显著提高其放电性能,100 mA下的放电容量达到3.14 Ah,显示出它在高能化学电源领域的应用前景.The zinc polyhedral microspheres were synthesized by evaporation of pure zinc powders via a vapor-transport process.The results characterized by XRD and SEM show that the as-synthesized zinc powders are polyhedral microspheres with the diameter of 2~3 μm.The electrochemical investigation showed that the capacity of the as-assembled AA-size primary alkaline Zn-MnO_(2)battery was increased to 3.14 Ah under the constant discharge current of 100 mA by using the as-deposited microspherical zinc powders as the anode active materials and γ-MnO_(2)nanowires as the cathode active materials,indicating their potential application in high-energy batteries.作者联系地址：南开大学新能源材料化学研究所,南开大学新能源材料化学研究所,南开大学新能源材料化学研究所,南开大学新能源材料化学研究所,南开大学新能源材料化学研究所,南开大学新能源材料化学研究所 天津300071,天津300071,天津300071,天津300071,天津300071,天津300071Author's Address: *Institute of New Energy Material Chemistry,Nankai University,Tianjin 300071,Chin

Electroless-deposition Synthesis of Highly Active PtRu/C and PtRuSn/C as Anode Catalysts for DEFC

应用化学镀方法,以活化-敏化处理的活性炭作载体,制备高分散催化剂PtRu/C和PtRuSn/C.XRD、TEM及电化学测试表明,该催化剂Pt、Ru、Sn形成合金.金属颗粒的平均粒径约为3 nm.PtRu/C和PtRuSn/C二者对乙醇的阳极氧化都具有良好的催化活性和稳定性.In this paper,the preparation,characterization,and ethanol electrocatalytic oxidation of Pt0.5Ru0.5/C and Pt0.5Ru0.15Sn0.35/C electrocatalysts were reported.The electroless-deposition with sensitization-activation pretreatment was applied to prepare Pt0.5Ru0.5/C and Pt0.5Ru0.15Sn0.35/C electrocatalysts. The XRD and TEM analyses showed that the as-prepared catalysts were composed of well-dispersed PtRu or PtRuSn nanoparticles with an average particle size of about 3 nm.The electrochemical measurements demonstrated that the as-prepared Pt0.5Ru0.5/C and Pt0.5Ru0.15Sn0.35/C catalysts exhibited much enhanced peak current density for ethanol electrooxidation as compared to that synthesized without pretreatment.This result revealed that the pretreatment is favorable to the dispersion,size distribution and alloy degree of the nanocatalysts on the carbon support.In particular,the peak current density of ethanol oxidation on Pt0.5Ru0.15Sn0.35/C was nearly twice larger than that of Pt0.5Ru0.5/C,indicating their potential application in DEFC with a synergic effect of Ru and Sn.作者联系地址：南开大学化学学院新能源材料化学研究所和能源材料化学天津市重点实验室,南开大学化学学院新能源材料化学研究所和能源材料化学天津市重点实验室,南开大学化学学院新能源材料化学研究所和能源材料化学天津市重点实验室,南开大学化学学院新能源材料化学研究所和能源材料化学天津市重点实验室,南开大学化学学院新能源材料化学研究所和能源材料化学天津市重点实验室,南开大学化学学院新能源材料化学研究所和能源材料化学天津市重点实验室,南开大学化学学院新能源材料化学研究所和能源材料化学天津市重点实验室 天津300071,天津300071,天津300071,天津300071,天津300071,天津300071,天津300071Author's Address: Institute of New Energy Material Chemistry and Key Laboratory of Energy Meterial Chemistry, Nankai University,Tianjin 300071,Chin