Promoting effect of Ru on Ni/Mg(Al)O catalysts in DSS-like operation of CH4 steam reforming

Miyata Takeshi

Shiraga Masato

Li Dalin

Atake Ikuo

Shishido Tetsuya

Oumi Yasunori

Sano Tsuneji

Takehira Katsuomi

Catalysis Communications

Effects of Ru addition on the activity and the sustainability of Ni/Mg(Al)O catalysts were investigated in the daily start-up and shut-down (DSS) operation of the steam reforming of CH4. Mg2.5(Ni0.5)-Al hydrotalcite was prepared by coprecipitation and calcined to form Mg2.5(Al,Ni0.5)O periclase. When the powders of the periclase were dipped in an aqueous solution of Ru(III) nitrate, the hydrotaclite was reconstituted on the surface of Mg2.5(Al,Ni0.5)O particles, resulting in the formation of highly dispersed Ru/Ni bimetal supported catalysts after the calcination, followed by the reduction. The addition of Ru on Ni caused a decrease in the reduction temperature of Ni and an increase in the amount of H2 uptake on the Ni over the catalyst. Formation of Ru-Ni alloy or strong interaction between Ru and Ni was also suggested. When Ru-Ni0.5/Mg2.5(Al)O catalysts were tested in the DSS-like operation under steam purging, the deactivation due to the oxidation of Ni metal by steam was effectively suppressed by hydrogen spillover. Moreover, only 0.05 wt0f Ru loading was enough to effectively suppress the deactivation during the DSS-like operation.

CH4 reforming

H2 production

DSS operation

Ni/Mg(Al)O catalyst

Ru addition

memory effect.

Chemistry [ 430 ]

eng

Elsevier

Copyright (c) 2007 Elsevier Ltd.

[ISSN] 1566-7367

[DOI] 10.1016/j.catcom.2006.07.018

[NCID] AA11528189

[DOI] http://dx.doi.org/10.1016/j.catcom.2006.07.018 isVersionOf