Dry reforming of methane over a Ni/Al2O3 catalyst in a coaxial dielectric barrier discharge reactor

Xin Tu (1) , Helen J Gallon (1) , Martyn V Twigg (2) , Peter A Gorry (1) , J Christopher Whitehead (1)

1 School of Chemistry
2 Orchard Laboratory

A coaxial double dielectric barrier discharge (DBD) reactor has been developed for plasmacatalytic conversion of CH 4 and CO 2 into syngas and other valuable products. A supported metal catalyst (Ni/Al 2 O 3) reduced in a methane discharge is fully packed into the discharge region. The influence of the Ni/Al 2 O 3 catalyst packed into the gas gap on the electrical characteristics of the discharge has been investigated. The introduction of the catalyst pellets leads to a transition in discharge behaviour from a typical filamentary microdischarge to a combination of spatially-limited microdischarges and a predominant surface discharge on the catalyst surface. It is also found that the breakdown voltage of the CH 4 /CO 2 discharge significantly decreases when the reduced catalyst is fully packed in the discharge area. Conductive Ni active sites dispersed on the catalyst surface contribute to the expansion of the discharge and enhancement of charge transfer. In addition, plasma-catalytic dry reforming of CH 4 has been carried out with the reduced Ni/Al 2 O 3 catalyst using a mixing ratio of CH 4 /CO 2 = 1 and a total flow rate of 50 ml min -1. An increase in H 2 selectivity is observed compared to dry CH 4 reforming with no catalyst, while the H 2 /CO molar ratio greatly increases from 0.84 to 2.53 when the catalyst is present.

Mots clés: Dielectric barrier discharge; Plasma-catalysis; Breakdown; Dry reforming; Hydrogen production; 52.80.-s; 52.40.Hf; 88.30.-k; 82.33.Xj

Xin Tu, Helen J Gallon, Martyn V Twigg, Peter A Gorry, J Christopher Whitehead. Dry reforming of methane over a Ni/Al2O3 catalyst in a coaxial dielectric barrier discharge reactor. Journal of Physics D: Applied Physics, 2011, 44 (27), pp.274007. ⟨10.1088/0022-3727/44/27/274007⟩. ⟨hal-00631679⟩