In Situ Mapping of H₂, O₂, and H₂O₂ in Microreactors: A Parallel, Selective Multianalyte Detection Method

Area of Science:

• Electrochemistry
• Chemical Engineering
• Analytical Chemistry

Background:

• Accurate monitoring of reactants and products in microreactors is crucial for process optimization and safety.
• Simultaneous detection of multiple analytes in microreactors presents significant challenges.
• Electrochemical microsensors offer high spatial and temporal resolution for in situ measurements.

Purpose of the Study:

• To develop a selective, parallel monitoring method for hydrogen, oxygen, and hydrogen peroxide in microreactors.
• To enable in situ kinetic analysis of the hydrogen peroxide synthesis process.
• To facilitate online process control through real-time analyte mapping.

Main Methods:

• A chronoamperometric approach using a single platinum microelectrode in an aqueous electrolyte.
• Utilizing three specific potentials for selective detection and subtraction of interfering currents.
• Employing linear superposition of signals for simultaneous analyte quantification.

Main Results:

• Selective detection of hydrogen, oxygen, and hydrogen peroxide was achieved.
• Interfering currents were successfully subtracted, yielding accurate analyte concentrations.
• Concentration measurements correlated well with results from non-interfering conditions.
• The first-time mapping of hydrogen, oxygen, and hydrogen peroxide distribution in a microreactor was demonstrated.

Conclusions:

• The developed electrochemical method allows for selective and simultaneous quantification of hydrogen, oxygen, and hydrogen peroxide.
• This approach overcomes limitations in monitoring multianalyte environments within microreactors.
• The ability to map analyte distribution paves the way for advanced online process control in microreactor systems.