Details

Autor(en) / Beteiligte

• Jiang, Changyi
• Loisel, Emily
• Cullen, David A.
• Dorman, James A.
• Dooley, Kerry M.

Titel

On the enhanced sulfur and coking tolerance of Ni-Co-rare earth oxide catalysts for the dry reforming of methane

Ist Teil von

• Journal of catalysis, 2021-01, Vol.393, p.215-229

Ort / Verlag

Elsevier Inc

Erscheinungsjahr

2021

Quelle

Access via ScienceDirect (Elsevier)

Beschreibungen/Notizen

• [Display omitted] •Sulfur tolerance of Ni-based dry reforming of methane catalysts examined.•Both Ce/Zr and Ce/La oxides with Ni are stable at low sulfur concentrations.•Only Ni-Co supported on Ce/Zr oxide not rapidly deactivated at >20 ppm sulfur.•Ni-Co catalysts also show much lower coking rates in dry reforming.•Improved performance linked to strong Co-Ni and strong metal-oxide interactions. Sulfur and coking tolerance of Ni-based dry reforming catalysts were examined. Catalysts utilizing both Ce/Zr and Ce/La oxide supports, some with additional Co, were tested. Long-term reaction runs were conducted with and without sulfur in the feed. Catalysts were also characterized by STEM, XPS, XAFS and XANES and CO chemisorption. Only catalysts where Co was also present, and supported on the Ce-Zr oxide, were capable of extended sulfur tolerance at >20 ppm sulfur. This tolerance, along with a greatly reduced coking rate, is linked to Co in intimate contact with Ni, the mixture existing as clusters anchored and influenced electronically by the oxide support. The activation of methane takes place on these sites. Larger metal aggregates formed by ripening during reaction appear to be spectators. The measured activation energies for dry reforming suggest that CO2 activation takes place at the oxide interface, and is a kinetically significant step.