Dry reforming of methane over the Ni/Y2O3-ZrO2 catalysts: Effects of the tunable surface oxygen species by modulating the zirconium precursors

The surface reactive oxygen species over Y 2 O 3 -ZrO 2 supports were tuned by regulating the interaction between Y and Zr via modulating the zirconium precursors. It was revealed that the content of the surface adsorbed oxygen species (SAOS) over the catalyst with ZrO 2 precursor was the highest, followed by the catalysts with Zr(OH) 4 and ZrO(NO 3 ) 2 ·2H 2 O precursors. The difference of the Y-Zr interaction influenced the reactive oxygen species and the support structure and morphology. However, Ni dispersion was determined by the existence of the isolated Y 2 O 3 due to the enhanced metal-support interaction. High Ni dispersion and abundant surface adsorbed oxygen species were beneficial to promote CH 4 and CO 2 reactivity. Nevertheless, CH 4 dissociation facilitated by the SAOS was more remarkable than CO 2 activation at low temperature. Thus, the improvement of the SAOS on carbon-resistant ability of the catalyst was only achieved at high temperature through balancing the carbon formation and elimination.