Evaluation of the dynamic electrochemical stability of ionic liquid-metal interfaces against reactive oxygen species using an in situ electrochemical quartz crystal microbalance

Details

• Personal Author:
  Rehman A ; Xiao C ; Zeng X
• Description:
  The dynamic interactions between the electrochemically generated superoxide radical (O2 .-) and three structurally different ionic liquids (ILs) were characterized using an electrochemical quartz crystal microbalance (EQCM). We established the long-term stability of the interface (on the scale of hours and weeks) against the most ubiquitous interferent in electrochemical energy devices and sensors: oxygen. Oxygen potentially limits the application of IL electrolytes in these devices. In particular, the electrochemical behavior of the O2/O2 .- couple and the ion pair formed between the cation of an IL and O2.- were evaluated. O2.- tends to form ion pair complexes with the cation of an IL, subsequently abstracting a proton to form different products depending on the cationic structure of the IL used. The reversibility of the O2/O2.- electrode reaction depends on the subsequent chemical reactions between O2.- and the IL, which are more pronounced at slow scan rates. It was found that O2.- was significantly more stable in the IL with the [BMPY] cation than in ILs with imidazolium salts. The stability of the ILs towards O2.- attack follows the order [BMPY][NTf2] > [BdMIM][NTf2] > [BMIM][NTf2] as evaluated on a time-scale of a few seconds to minutes and up to 3 weeks. It was found that the formation of the [Cation]...O2.- ion pair complex lowers the local viscosity of the IL near the electrode, reflected in the change in the oscillating frequency of the quartz crystal electrode. As much as is the feasibility for the formation of this ion pair, that much is the tendency of the IL to lose its electrochemical stability. A combined analysis can provide a quick indication of the dynamic stability of the electrode-electrolyte interface for any IL in the presence of certain electrochemical reactions using the EQCM technique. [Description provided by NIOSH]
• Subjects:
  Behavior Chemistry Occupational Health Oxygen Safety
• Keywords:
  Chemical Reactions Electrolytes Sensors Viscosity
• ISSN:
  2046-2069
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Michigan ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  5
• Issue:
  40
• NIOSHTIC Number:
  nn:20048649
• Citation:
  RSC Adv 2015 Mar; 5(40):31826-31836
• Contact Point Address:
  Xiangqun Zeng, Department of Chemistry, Oakland University, Rochester, USA
• Email:
  zeng@oakland.edu
• CAS Registry Number:
  Oxygen (CAS RN 7782-44-7)
• Federal Fiscal Year:
  2015
• Performing Organization:
  Michigan State University
• Peer Reviewed:
  True
• Start Date:
  20100901
• Source Full Name:
  Royal Society of Chemistry Advances
• End Date:
  20150831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:d79dfb9da7f081ceccfb9dae8b70de3a93b9832f430dd8b14ee6852e3ed2aeca26954ccca678b0a98c8b7a1d3e26de9d29ce72e0a6faf44bcd052dc00b3d6fd2
• Download URL:
  https://stacks.cdc.gov/view/cdc/203357/cdc_203357_DS1.pdf
• File Type:
  [PDF - 1.31 MB ]