粉丝服务

原位电化学质谱（DEMS）与原位电化学红外光谱（in situ EC-FTIR）在电化学反应机理研究中的应用


目前，对于电化学反应气相产物或挥发性产物，大多是建立在稳态极化和色谱分析的基础上，稳态极化只能反映总反应电流而无法分辨各分步反应状况，对于大多数电化学研究而言，电位动态扫描或电位调制过程中的现场研究更有研究价值，原位电化学质谱仪(DEMS)是一种将电化学反应池与质谱仪联用,在电位动态扫描或电位调制过程中，能毫秒内时间分辨地进行物质定性或定量分析的仪器，可应用于电催化和电池原位测试，是研究电化学反应机理、快速筛选、评价电化学反应材料和催化剂的重要工具。

➸1 原位电化学质谱DEMS（电池、电催化）

1.1电催化DEMS应用概况

具体应用：

1.CO2电催化还原气相产物(CO,CH4,C2H4,CH3OH等)瞬时检测，相对法拉第效率测定；

2.硝酸根电催化还原中NO,N2O,NH2OH,NH3,N2等中间产物或最终产物原位检测；

3.电解水OER同位素标记18O，LOM或AEM反应机理确认；

4.甲醇电氧化反应中间产物或最终产物（HCHO，HCOOH，CO等）瞬时检测及各产物电流效率计算；

5.氢同位素标记，氢气析出反应（HER）机理解析；

6.碳材料稳定性评估（高电位下CO，CO2检测）；

7.其他（光催化，光电催化，氧还原，氢氧化，氯气析出，有机电合成等）。


原位微分电化学质谱仪(DEMS)在电催化测试中，依靠真空压差作为动力，通过阻水透气膜将电极表面电化学反应产生的气体或挥发性产物或中间产物在毫秒时间内，抽取到质谱仪中，从而实现高灵敏度、高分辨率地检测到产物，主要应用于MOR，EOR，CO2RR，HER，OER，ORR，NRR，硝酸根还原，氨氧化等电催化反应中。


应用案例：
1.硝酸根电还原中间体检测

Linear Sweep Voltammetry during DEMS mearements: applied voltage from 0.05 to -0.95V. The NRA performance was recorded versus a saturated calomel electrode(SCE)in 0.5M Na2SO4 electrolyte with 200 ppm nitrate-N. DEMS measurements of NRA over Cu/Cu2ONWAs.
Angew. Chem. Int. Ed. 10.1002/anie.201915992

2.电解水OER同位素标记18O，LOM或AEM反应机理确认

DEMS signals of 32O2 (15O16O) and 34O2 (16O18O) from the reaction products for 18O-labeled SrRulr and RuO2 catalysts in H218O aqueous sulfuric acid electrolyte and corresponding CV cycles. The mass spectroscopy signals are baseline subtracted.

J. Am. Chem. Soc. 2021, 143, 17, 6482-6490


3.甲醇电氧化反应

Simultaneously recorded CV and MSCVs for methanol electrooxidation on Pt/C in 1 M methanol and 0.5 M H2SO4 solution at the scan rate of 1 mV s-1. Electrolyte flow rate of 2.67ml min-1, distance of 50 µm. Arrows indicate the direction of potential scan. 
Journal of Power Sources 509 (2021) 230397

4.氢同位素标记，氢气析出反应（HER）机理解析

DEMS signals at m/z=2,3 and 3 at a pulsed potential of 0.3V RHE over the Cu catalyst in 1 M KOH with 50 mM deuterated benzaldehyde.
Nature catalysis, 2022,5,66-73

5.CO2电还原

(a) Polarization curves of Au(hkl) recorded in a CO2-saturated 0.1 M KHCO3solution at 1 mV/s. (b) Normalized Q-mass ion currents for hydrogen, carbon monoxide, and methane detected by OLEMS with dependence of the applied cathodic potential. Insets are magnififications of the onset potential regions.
ACS catal. 2019,9,1383-1388

1.2电池DEMS应用概况

主要应用如下：

  • 富锂正极材料首次充电O2析出定量检测

  • 高压钴酸锂首次充电O2析出定量检测

  • 高镍正极材料首次充电O2析出定量检测

  • 钠离子电池正极首次充电O2析出检测

  • 负极材料放电过程中气体析出检测

  • 锂离子电池电解液分解气体析出检测

  • 水系锌离子电池充放电气体析出检测

  • Li-O2电池充放电过程O2检测

  • Li-CO2电池充放电过程中CO2气体检测


原位电化学质谱仪(DEMS，OLEMS，OEMS)在电池测试中，能够原位分析锂离子电池、钠离子电池、金属空气电池等储能器件在运行过程中产生或消耗的微量气体，可以实时分析检测电池运行的不同阶段的气体消耗或生成情况，从而获得电化学反应中气体参与或气体释放的定性定量信息。

应用案例如下：
1.富锂正极材料首次充电O2析出定量检测

Fig1. Operando DEMS results for (a) PL and (b) LF-10 electrodes. The black solid lines and brown dots correspond to the voltage profile and O2 evolution, respectively
Angew. Chem. 2020,132,23261-23266

2.高压钴酸锂首次充电O2析出定量检测

Fig.2 DEMS profiles during the first charging process of a) the Bare-LCO and b) the OIN-LCO to 4.6 V 
Adv. Sci. 2022, 2104841

3.高镍正极材料首次充电O2和CO2析出定量检测

O2 and CO2 evolution rates during in-situ DEMS measurements and the corresponding voltage profiles of NCA and NCAT1 cycled at 0.1C between 3.0 and 4.7 V
Small 2021, 2104282

4.钠离子电池正极首次充电O2析出检测

In situ DEMS analysis of oxygen release during the first charge for the Na2/3Ni1/3Mn2/3O2electrode. The charge current density is 10 µAmg-1 and the cut off voltage is 4.3 V.
ACS Central Science 2020, 6 (2), 232-240

5.负极材料放电过程中气体析出检测

Characterization of gaseous and solid byproducts of electrolyte decomposition on Sn electrode surface. (a) In situ differential electrochemical mass spectrometry (DEMS) analysis of gaseous products by a Sn//Li half-cell, where H2 (the black), CO2(the red) and CnH2n (the blue, green and pink) were detected. The Sn//Li half-cell was lithiated to 3 mA h and then delithiated to 1.5 V.
Energy Environ. Sci., 2019, 12, 2991--3000

6.锂离子电池电解液分解气体析出检测

Gas evolution during the first three formation cycles of a pristine graphite working-electrode vs. a metallic lithium counter-electrode in 1 M LiTFSI in EC/EMC (<20 ppm H2O). The upper panel displays the current potential curve corresponding to the CV formation procedure between 0 - 1.5VLi at a scan rate of 0.5 mV/s. The middle panel shows the gas concentration in the cell head space during formation in units of [ppm] for H2 (m/z = 2),C2H2 (m/z = 26), and CO2 (m/z = 44). The bottom panel contains the corresponding gas evolution rates in [pmm/s] (2h OCV phase prior to formation not shown).
Journal of The Electrochemical Society, 162 (10) A1984-A1989 (2015)

7.锌离子电池

Electrochemical window of the Li–H2O–MU0.00 and Li–H2O–MU0.27 electrolytes evaluated by LSV tests on carbon-coated Al electrode, together with H2 and O2 evolutions monitored by in situ DEMS during the cathodic and anodic scans. Clearly, both H2 and O2 evolutions are efficiently suppressed in the Li–H2O–MU0.27 electrolyte, particularly, the cathodic limit is dramatically decreased from 1.8 to 0.5 V, versus Li+/Li. With the improved electrochemical window, charge-discharge of low-potential and high-capacity NbO2 electrode can be fully operated in the Li–H2O–MU0.27 electrolyte.
https://doi.org/10.1016/j.joule.2022.01.002

8.Li-O2电池充放电过程O2检测

Li-O2电池DEMS analyses in the Swagelok LOBs without (e, f) 0.5 mg ml-1Au nanocolloid electrolyte in discharge (e) and charge (f)processes.
ACS Appl. Mater.Interfaces, 2021, D01:10.1021/acsami.0c20871

9.Li-CO2电池充放电过程中CO2气体检测

DEMS results of (a) and (b) discharging TiO2/CC cathode with and without illumination in the first cycle of Li-CO2 battery. DEMS results of (c) and (d) charging TiO2/CC cathode with and without illumination in the first cycle of Li-CO2 battery.
Small 2021, 17, 2100642，DOI: 10.1002/smll.202100642


➸2 原位电化学红外光谱（电池、电催化）

2.1电催化原位红外光谱

利用分子振动的特征吸收，红外光谱可以用于原位检测固体电极上的吸附态物种，从而：(1) 关键中间产物的识别和构型鉴定，（2）确定电极表面成键状态（3）优先的反应路径和选择性确认（4）探究反应环境的影响，如电解液阴离子，阳离子，pH, 添加剂等（5）电极电解液界面双电层的探测。适用于水系或非水系电催化反应，如CO2RR,，HER， OER，ORR，MOR， EOR，NRR，硝酸根还原，有机电合成等。


内反射模式（表面增强红外ATR-SEIRAS）：
可得到电催化吸附态产物或中间产物信息

外反射模式(IRRAS)：
可得到吸附态和溶液相中间产物或最终产物信息

应用案例：
1.CO2电还原反应中间体检测

原位ATR-SEIRAS光谱，将施加的电位从-0.4降低到-1.8V，同时记录所有光谱
Nature Communications, 2022 13:63

2.氢氧燃料电池电催化

In-situATR-SEIRAS spectra recorded during stepping the potential from 0.2 to −0.15 V vs. RHE in  H2-saturated 0.1 M KOH electrolyte for a-b Ru/C, c-d Ru7Ni3/C and e-f Acid-Ru7Ni3/C.
Nature Communications, 2020 11:5651

2.2电池原位红外光谱
适用于锂离子电池、锂硫电池、钠离子电池、锂氧气电池、锌离子电池等非水系或水系电池体系，探究正极材料、负极材料、SEI膜、电解液分解、溶剂化以及锂离子动力学行为。


➸3 公司情况：

3.1公司在上海设有原位电化学质谱和原位电化学红外分析测试实验室，可为客户提供测样平台，实地调研仪器

3.2质谱仪软件与电化学工作站软件偶合，实时同步采集

3.3强大的应用及售后工程师团队，具有电化学、质谱、真空、红外相关领域专业知识

3.4客户情况：北京大学、清华大学、复旦大学、同济大学、武汉大学、南开大学、天津大学、吉林大学、中国科学院长春应用化学研究所、宁德时代……百余所高校及企业。

3.5服务客户已在知名国际期刊发表高水平论文200余篇



欢迎来电或来访咨询 

手机/微信：13651655649

座   机：021-50670008

公    司：上海零露仪器设备有限公司

地    址：上海市浦东新区兰嵩路555号森兰美伦A座208室

网    址：www.linglush.com

   

本栏目精选

热门推荐

频道导航

科技娱乐汽车体育财经旅游育儿历史美食军事国际情感