Parametric analysis of plasma‐assisted pulsed dry methane reforming over Ni/Al 2 O 3 catalyst

Pulsed dry methane reforming (DMR) with CH 4 /CO 2 ratios of 0.5–2.0 was investigated in a dielectric barrier discharge (DBD) and Ni/Al 2 O 3 hybrid reaction. A pulsed CH 4 supply allows alternating DMR and de‐coking reactions, thus enabling reaction diagnostics without serious catalyst deactivation by coking. Parametric changes in the CH 4 /CO 2 ratio were used to probe the rate‐determining step and synergistic effect induced by DBD. Nonthermal plasma‐activated CO 2 and H 2 O were found to be key factors for enhancing the H 2 and CO yields and CO 2 conversion. In contrast, CH 4 conversion was not clearly enhanced by DBD at fixed temperatures near 550 °C. Moreover, based on experimental observations, a tentative mechanism was proposed wherein a trace amount of plasma‐excited H 2 O catalytically promoted solid carbon oxidation.