LAUSR

Abstract Phosphorous-modified γ-Al 2 O 3 support is used to prepare cobalt-based catalysts (CoP(x)Al, x = 0–4 wt%) for dry reforming of methane (DRM). From the studied catalysts, CoAl displays the highest conversions of CH 4 and CO 2 at the initial stage due to good cobalt dispersion. However, both conversions decrease significantly after 20 h on stream due to the formation of inactive CoAl 2 O 4 phase through the reaction of oxidized CoO x with the alumina surface. For the CoP(x)Al catalysts, although the initial CH 4 and CO 2 conversions decrease gradually as the phosphorus loadings increased, all catalysts show more stable catalytic activity than the CoAl catalyst. Formation of aluminum phosphate (AlPO 4 ) on the alumina surface can be achieved by the addition of phosphorus. The AlPO 4 phase has the capacity to suppress the formation of CoAl 2 O 4 phase. Phosphorous loadings on alumina surface of up to 1–2 wt% exerted positive effect on catalyst stability, whereas loadings above this threshold exerted opposite effect.