Barium-Promoted Yttria-Zirconia-Supported Ni Catalyst forHydrogen Production via the Dry Reforming of Methane: Role ofBarium in the Phase Stabilization of Cubic ZrO2

:developing cost-effective nonprecious active metal-basedcatalysts for syngas (H2/CO) production via the dry reforming of methane(DRM) for industrial applications has remained a challenge. Herein, weutilized a facile and scalable mechanochemical method to develop Ba-promoted (1-5 wt %) zirconia and yttria-zirconia-supported Ni-basedDRM catalysts. BET surface area and porosity measurements, infrared,ultraviolet-visible, and Raman spectroscopy, transmission electronmicroscopy, and temperature-programmed cyclic (reduction-oxidation-reduction) experiments were performed to characterize and elucidate thecatalytic performance of the synthesized materials. Among differentcatalysts tested, the inferior catalytic performance of 5Ni/Zr was attributedto the unstable monoclinic ZrO2support and weakly interacting NiOspecies whereas the 5Ni/YZr system performed better because of the stablecubic ZrO2phase and stronger metal-support interaction. It is establishedthat the addition of Ba to the catalysts improves the oxygen-endowing capacity and stabilization of the cubic ZrO2and BaZrO3phases. Among the Ba-promoted catalysts, owing to the optimal active metal particle size and excess ionic CO32-species, the5Ni4Ba/YZr catalyst demonstrated a high, stable H2yield (i.e., 79% with a 0.94 H2/CO ratio) for up to 7 h of time on stream. The5Ni4Ba/YZr catalyst had the highest H2formation rate, 1.14 mol g-1h-1and lowest apparent activation energy, 20.07 kJ/mol,among all zirconia-supported Ni catalyst systems

Automated summary

In this study, Ba-promoted Ni-based catalysts supported by ZrO2 and YZr were successfully developed for the dry reforming of methane. The addition of Ba improved the oxygen-endowing capacity and stabilization of the catalysts, resulting in higher H2 yield and stability. This research provides cost-effective nonprecious active metal-based catalysts for syngas production.