Catalytic Ignition and Pressure Dependence of Methane/Air Combustion over Palladium Oxide

Abstract

The catalytic ignition and kinetics of CH4/air oxidation over PdO were studied using wire microcalorimetry. Ignition temperatures and heat release rates were measured and global kinetic parameters were extracted. Key reactions rates were amended and a detailed surface reaction scheme for atmospheric pressure was proposed. In a subsequent step, the pressure dependence of CH4/air catalytic oxidation over PdO was investigated in the range 1-12 bar in a channel-flow catalytic reactor. In situ Raman measurements of major gas phase species concentrations assessed the heterogeneous reactivity, while planar laser induced fluorescence (LIF) of the OH radical monitored homogeneous combustion. Simulations were performed using a 2-D code with detailed hetero-/homogeneous reaction mechanisms. Comparisons between Raman measured and numerically predicted profiles of major species allowed for the construction of a global catalytic step valid for 1-12 bar. The CH4 catalytic reaction rate had an overall pressure dependence ∼p1-n where the exponent n was itself a monotonically increasing function of pressure. This resulted in non-monotonic pressure dependence, a behavior in stark contrast to other noble metals such at Pt and Rh.

Meeting Name

2018 Spring Technical Meeting of the Eastern States Section of the Combustion Institute, ESSCI 2018 (2018: Mar. 4-7, State College, PA)

Department(s)

Mechanical and Aerospace Engineering

Comments

This research was funded by Swiss National Science Foundation EPM fellowship and EU project HRC-Power.

Keywords and Phrases

Catalytic ignition; Methane total oxidation over PdO; Pressure dependence of catalytic reactivity

Document Type

Article - Conference proceedings

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2018 Eastern States Section of the Combustion Institute, All rights reserved.

Publication Date

01 Mar 2018

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