- Mass spectrometry
- Fuel cell development
- Enables quantitative real time analysis of gaseous or volatile electrochemical reaction products
- Rapid response time (~1 s)
- High product collection efficiency
- Parallel electrode geometry ensures uniform potential applied across the working electrode surface
- Ion-conducting membrane separates the electrodes to prevent unwanted reactions
- Low cell resistance (~50 Ω)
- Compatible with an inert glassy carbon electrode
- Efficient and economical electrochemical cell design
Berkeley Lab researchers at the Joint Center for Artificial Photosynthesis (JCAP) have created a differential electrochemical mass spectrometer (DEMS) cell with a modified electrode that enables the quantitative analysis of electrochemical reaction products in real time. The Berkeley Lab DEMS enables the transient selectivity of novel electrocatalysts to be continuously quantified at a fixed potential. The DEMS cell also enables the partial current potential dependence of the major electrochemical reaction products to be rapidly determined in approximately one hour by sweeping the applied potential and recording the product generation rates in real time. Establishing these trends with the traditional methods can take several days of experimentation.
Electrochemical reactions, such as the reduction of CO2 or the oxidation of organic compounds, can produce a variety of different reaction products. As a result, performing quantitative product analysis is critical when studying novel electrocatalytic systems. Since these electrochemical reaction products can be in the gas phase or dissolved in the electrolyte, a variety of analytical techniques are typically employed, such as a combination of gas chromatography and either liquid chromatography or nuclear magnetic resonance, to fully characterize the selectivity of a given electrocatalyst. However, the reliance on chromatography limits the timescale of product analysis and makes it very difficult to study electrocatalytic systems that experience rapid deactivation or undergo selectivity changes over their operational lifetime.
As a result there is significant interest in the scientific community in the development of an analytical technique capable of quantifying electrochemical reaction products in both phases in real time. The Berkeley Lab DEMS cell satisfies all of the requirements for accurate electrochemistry while also enabling volatile reaction products to be quantified in real time.
STATUS: Patent pending. Available for licensing or collaborative research.
DEVELOPMENT STAGE: Functional prototype
REFERENCE NUMBER: 2014-102