Probing the Role of a Non-Thermal Plasma (NTP) in the Hybrid NTP Catalytic Oxidation of Methane

Emma K Gibson; Cristina E Stere; Bronagh Curran-McAteer; Wilm Jones; Giannantonio Cibin; Diego Gianolio; Alexandre Goguet; Peter P Wells; C Richard A Catlow; Paul Collier; Peter Hinde; Christopher Hardacre

doi:10.1002/anie.201703550

Probing the Role of a Non-Thermal Plasma (NTP) in the Hybrid NTP Catalytic Oxidation of Methane

Angew Chem Int Ed Engl. 2017 Aug 1;56(32):9351-9355. doi: 10.1002/anie.201703550. Epub 2017 Jul 6.

Authors

Emma K Gibson^{1

2}, Cristina E Stere³, Bronagh Curran-McAteer⁴, Wilm Jones^{1

5}, Giannantonio Cibin⁶, Diego Gianolio⁶, Alexandre Goguet⁴, Peter P Wells^{1

6

7}, C Richard A Catlow^{1

2

5}, Paul Collier⁸, Peter Hinde⁸, Christopher Hardacre³

Affiliations

¹ UK Catalysis Hub, Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell Oxon, Didcot, OX11 0FA, UK.
² Department of Chemistry, University College London, 20 Gordon Street, London, WC1 0AJ, UK.
³ School of Chemical Engineering & Analytical Science, University of Manchester, The Mill (C56), Sackville Street, Manchester, M13 9PL, UK.
⁴ School of Chemistry and Chemical Engineering, Queen's University Belfast, Belfast, BT9 5AG, N. Ireland, UK.
⁵ Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Cardiff, CF10 3AT, UK.
⁶ Diamond Light Source, Harwell Science and Innovation Campus, Chilton, Didcot, OX11 0DE, UK.
⁷ School of Chemistry, University of Southampton, Southampton, SO17 1BJ, UK.
⁸ Johnson Matthey Technology Centre, Reading, UK.

Abstract

Three recurring hypotheses are often used to explain the effect of non-thermal plasmas (NTPs) on NTP catalytic hybrid reactions; namely, modification or heating of the catalyst or creation of new reaction pathways by plasma-produced species. NTP-assisted methane (CH₄ ) oxidation over Pd/Al₂ O₃ was investigated by direct monitoring of the X-ray absorption fine structure of the catalyst, coupled with end-of-pipe mass spectrometry. This in situ study revealed that the catalyst did not undergo any significant structural changes under NTP conditions. However, the NTP did lead to an increase in the temperature of the Pd nanoparticles; although this temperature rise was insufficient to activate the thermal CH₄ oxidation reaction. The contribution of a lower activation barrier alternative reaction pathway involving the formation of CH₃ (g) from electron impact reactions is proposed.

Keywords: EXAFS spectroscopy; heterogeneous catalysis; methane; non-thermal plasma; oxidation.

Publication types

Research Support, Non-U.S. Gov't