Plasma-assisted reduction of a NiO/Al2O3 catalyst in atmospheric pressure H2/Ar dielectric barrier discharge

• Published in: Catalysis today Vol. 211; pp. 120 - 125
• Main Authors: Tu, X., Gallon, H.J., Whitehead, J.C.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.08.2013; Elsevier
• Subjects: atmospheric pressure; Catalysis; Catalyst reduction; catalytic activity; Chemistry; Dielectric barrier discharge; Exact sciences and technology; General and physical chemistry; Non-thermal plasma; Plasma reduction; Plasma-catalysis; temperature; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Plasma reduction; Non-thermal plasma; Dielectric barrier discharge; Plasma-catalysis; Catalyst reduction; Aluminium oxide; Plasma; Binary compound; Catalytic reaction; Atmospheric pressure; Chemical reduction; Heterogeneous catalysis; Alumina; Catalyst
• ISSN: 0920-5861; 1873-4308
• DOI: 10.1016/j.cattod.2013.03.024

Time evolution of discharge power and temperature during reduction of NiO/Al2O3 in a 20vol.% H2/Ar DBD. •NiO/Al2O3 catalyst has been reduced in a H2/Ar plasma at low temperature.•Plasma reduction does not change Ni nanoparticles size on the catalyst surface.•Formation of Ni active sites on the catalyst surface changes plasma properties.•Dispersion of Ni sites contributes to the expansion of discharge across the gap.•Free electrons generated by Ar plasma cannot reduce NiO to Ni at low temperature. Plasma-assisted reduction of a NiO/Al2O3 catalyst has been carried out in a H2/Ar dielectric barrier discharge at atmospheric pressure and low temperature (<300°C). The time evolution of H2 consumption, the gaseous products, as well as the discharge power and temperature during the plasma reduction of NiO/Al2O3 have been investigated to get a better understanding of the reduction mechanisms involved in the plasma process. The effect of the Ni conductive metal sites on the physical characteristics of the H2/Ar discharge has also been examined. The results show that the discharge power linearly increases during the plasma-reduction process, accompanied by an increase in transferred charge from 88nC to 119nC due to the formation of more conductive metallic Ni in the discharge gap. It is also found that plasma reduction does not change the size of Ni particles.