Plasma-assisted methane reduction of a NiO catalyst—Low temperature activation of methane and formation of carbon nanofibres

The low temperature reduction of a NiO catalyst by CH4 was performed in a coaxial double dielectric barrier discharge (DBD) reactor for the first time. The reduction involves active surface carbon which is produced via plasma decomposition of CH4. On the reduced Ni catalyst, activation of CH4 and its fragments to form H2 and carbon nanofibres occurred at 330 °C. CH4 conversions of 37% were achieved in the plasma-catalytic reaction at atmospheric pressure, with 99% selectivity towards H2 and solid carbon. These results demonstrate a synergistic effect where both the plasma and catalyst are vital for the production of H2 and carbon nanofibres. In the absence of the catalyst stable plasma could not be ignited with a pure CH4 flow and thermal studies showed that in the absence of the plasma CH4 conversion was minimal.

Graphical abstractCarbon nanofibre produced on a Ni catalyst by a low temperature methane plasma.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights• A low temperature methane plasma is used to reduce a NiO catalyst for the first time. • The reduced catalyst is used for the low temperature reforming of methane into hydrogen. • Carbon nanofibres are produced on the Ni catalyst by a low temperature methane plasma.