Strong activity-based volcano-type relationship for dry reforming of methane through modulating Ni-CeO2 interaction over Ni/CeO2-SiO2 catalysts

Abstract

The dry reforming of methane (DRM) reaction holds significance for efficient conversion of CH₄ and CO₂ into syngas for the subsequent production of premium fuels and high-value chemicals. However, catalyst deactivation is easily caused by carbon deposition over Ni-based catalysts. Here, we investigated the effects of ultrasmall CeO₂ nano-islands on the DRM reaction and found a strong volcano-type relationship between CeO₂ content and reaction activity over Ni/CeO₂-SiO₂ catalysts. A suitable CeO₂ amount can only slightly suppress CH₄ dissociation but largely promote carbon species elimination. More importantly, the presence of these CeO₂ nano-islands positively affected the types and location of coke species by “carbon-phobic effect” and thus alleviated coverage of Ni active sites. As a result, a higher TOF_CH4 was obtained by an increase of about 82% and a continuous 2,000-h run almost without any side reaction, and deactivation was achieved along with CO₂ and CH₄ conversions at about 96% and 92%, respectively.