A novel Ba_1.15La_1.85In₂O_7-δ-based amperometric sensor for hydrogen and steam analysis at reduced operating...

Area of Science:

• Materials Science
• Electrochemistry
• Chemical Engineering

Background:

• Accurate monitoring of water vapor (H2O) and hydrogen (H2) is crucial for industrial processes, but existing solid-state electrochemical sensors face challenges like low sensitivity, cross-sensitivity, and degradation.
• These limitations hinder efficiency, safety, and control in chemical synthesis, energy conversion, and fuel cell technologies.

Purpose of the Study:

• To develop a novel amperometric solid-state sensor that overcomes the stability-selectivity trade-off of current devices.
• To enable precise, in-situ analysis of water vapor and hydrogen in complex industrial gas streams.

Main Methods:

• Fabrication of an amperometric solid-state sensor utilizing a newly engineered proton-conducting electrolyte: Ba1.15La1.85In2O7-δ.
• Evaluation of the sensor's performance, including sensitivity, selectivity, stability, and response/recovery times, under industrially relevant conditions (350-450 °C).

Main Results:

• The Ba1.15La1.85In2O7-δ based sensor demonstrated high proton conductivity and exceptional chemical stability below 500 °C.
• The sensor exhibited a distinct quantitative limiting current response to both H2 and H2O with minimal cross-interference.
• Accurate analysis of water vapor (1.3-10.0 vol%) and hydrogen (0.8-6.0 vol%) was achieved with high signal stability, linear response, and fast response/recovery times.

Conclusions:

• The Ba1.15La1.85In2O7-δ based electrochemical cell represents the first dual-function (H2/H2O) amperometric sensor validated for industrial conditions.
• This material class offers a stable, linear, and selective response, paving the way for high-performance amperometric sensors and a shift from conventional electrolytes.
• The sensor provides a reliable pathway for in-situ analysis in complex gas streams, enhancing process control and safety.