Engineering of surface properties of Ni-CeZrAl catalysts for dry reforming of methane

Abstract Ni-CeZrAl catalyst prepared by a facile co-precipitation method was applied for dry reforming of methane (DRM). DRM catalytic performance of Ni-CeZrAl presented the highest methane conversion of 38.1% at 650 °C, and remained stable at 700 °C for 50 h without deactivation. Kinetic investigations further showed the lowest apparent activation energy (34.5 kJ/mol) of DRM reaction and the highest CH4 TOF value (7.62 × 10−2 s−1) at 640 °C over Ni-CeZrAl. The surface properties of these samples were systematically characterized by H2-chemisorption, H2-TPR, XPS, Raman, CO2-TPD and O2-TPD. It can be found that the superior catalytic behaviors of Ni-CeZrAl catalyst were closely associated with its high dispersion of surface Ni0 active phase. More importantly, ample oxygen vacancies and basic sites favored the formation of disordered carbon and effectively protected the Ni active sites. The inferior activity in Ni-CeAl was due to the formation of NiAl2O4 inactive spinel phase. Similarly, weak interaction and fewer active sites resulted in the inferior catalytic performance of Ni-CeZr. Hence, unique surface properties of Ni-CeZrAl with the optimum active site-support interaction were responsible for considerable performance. This work provides a guidance to design high performance Ni-based catalysts for DRM.