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<p>Hydrogen catalytic ignition on platinum surfaces plays a critical role in hydrogen-fueled combustion systems, particularly in hydrogen internal combustion engines, where unintended surface-induced ignition may trigger abnormal-combustion phenomena. In this study, the surface ignition temperature of hydrogen–air mixtures on a platinum surface was systematically investigated under varying excess air ratios and initial pressures using a constant-volume combustion chamber equipped with an electrically heated platinum wire and optical pyrometer. A one-dimensional catalytic combustion model was developed in Cantera and benchmarked against experimental data to analyze the underlying heterogeneous reaction behavior. Under stoichiometric conditions (<i>λ</i> = 1.0), the measured surface ignition temperature reached 1133&#xa0;K, providing a quantitative reference for platinum-promoted hydrogen ignition. The experimental results show that the surface ignition temperature decreases with increasing excess air ratio in the ultra-lean regime (<i>λ</i> &gt; 1.0), which can be attributed to reduced hydrogen surface coverage and relatively enhanced oxygen adsorption/dissociative adsorption, thereby advancing the onset of catalytic heat release. A practical lean limit was observed at <i>λ</i> ≤ 0.8, where catalytic ignition could no longer be sustained under the applied heating conditions, indicating insufficient surface reactivity and heat release feedback. The surface ignition temperature decreases significantly with increasing initial pressure from 1 to 8&#xa0;bar(a), with a weaker decline at elevated pressures (6–8&#xa0;bar(a)), consistent with a transition from adsorption-enhanced reactivity to coverage-limited surface behavior at elevated pressure. While the numerical simulations capture the overall experimental trends, deviations observed at elevated pressures and lean conditions highlight the influence of surface saturation and pressure-dependent adsorption–desorption dynamics. Compared with prior studies that primarily examine hydrogen on other metal catalysts or treat platinum under idealized/low-pressure conditions, this work provides a systematic, engine-relevant characterization of platinum-promoted hydrogen ignition thresholds as functions of λ and pressure. Benchmarking the one-dimensional model against these data underscores the need for pressure- and coverage-dependent surface kinetics and product-inhibition effects. The novelty of this work is the systematic quantification of ignition boundaries (including a stoichiometric reference point and a practical lean limit) over a wide range of excess air ratios and elevated pressures, together with an experimentally anchored dataset for model development and ignition control. These results provide practical criteria for assessing platinum-related surface ignition risk in hydrogen-fueled devices and for defining operating margins with respect to mixture leanness and pressure. The measurement-based trends and limits also constrain catalytic ignition models used for ignition control design and abnormal-combustion mitigation.</p>

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Numerical and experimental investigation of the surface ignition temperature for hydrogen-air mixture in catalytic combustion on platinum surface

  • 期刊论文

  • 发表日期：

    2026年1月27日

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  • Xing Fudong,
  • Sascha Holzberger,
  • Maurice Kettner,
  • Jan Martin Hertweck,
  • Jens Denecke,
  • Miao Xuelong

摘要

Hydrogen catalytic ignition on platinum surfaces plays a critical role in hydrogen-fueled combustion systems, particularly in hydrogen internal combustion engines, where unintended surface-induced ignition may trigger abnormal-combustion phenomena. In this study, the surface ignition temperature of hydrogen–air mixtures on a platinum surface was systematically investigated under varying excess air ratios and initial pressures using a constant-volume combustion chamber equipped with an electrically heated platinum wire and optical pyrometer. A one-dimensional catalytic combustion model was developed in Cantera and benchmarked against experimental data to analyze the underlying heterogeneous reaction behavior. Under stoichiometric conditions (λ = 1.0), the measured surface ignition temperature reached 1133 K, providing a quantitative reference for platinum-promoted hydrogen ignition. The experimental results show that the surface ignition temperature decreases with increasing excess air ratio in the ultra-lean regime (λ > 1.0), which can be attributed to reduced hydrogen surface coverage and relatively enhanced oxygen adsorption/dissociative adsorption, thereby advancing the onset of catalytic heat release. A practical lean limit was observed at λ ≤ 0.8, where catalytic ignition could no longer be sustained under the applied heating conditions, indicating insufficient surface reactivity and heat release feedback. The surface ignition temperature decreases significantly with increasing initial pressure from 1 to 8 bar(a), with a weaker decline at elevated pressures (6–8 bar(a)), consistent with a transition from adsorption-enhanced reactivity to coverage-limited surface behavior at elevated pressure. While the numerical simulations capture the overall experimental trends, deviations observed at elevated pressures and lean conditions highlight the influence of surface saturation and pressure-dependent adsorption–desorption dynamics. Compared with prior studies that primarily examine hydrogen on other metal catalysts or treat platinum under idealized/low-pressure conditions, this work provides a systematic, engine-relevant characterization of platinum-promoted hydrogen ignition thresholds as functions of λ and pressure. Benchmarking the one-dimensional model against these data underscores the need for pressure- and coverage-dependent surface kinetics and product-inhibition effects. The novelty of this work is the systematic quantification of ignition boundaries (including a stoichiometric reference point and a practical lean limit) over a wide range of excess air ratios and elevated pressures, together with an experimentally anchored dataset for model development and ignition control. These results provide practical criteria for assessing platinum-related surface ignition risk in hydrogen-fueled devices and for defining operating margins with respect to mixture leanness and pressure. The measurement-based trends and limits also constrain catalytic ignition models used for ignition control design and abnormal-combustion mitigation.