Effects of Metal-Support Interactions and Interfaces on Catalytic Performance over M2O3- ( M = La , Al-) Supported Ni Catalysts

Abstract

The metal-support interactions and their interfaces have showed great influence on catalytic activity and stability. Herein, different support of M2O3- ( $M=\text{La}$ , Al-) supported Ni catalysts was prepared by a citric acid-assisted sol-gel method. The physical structure and chemical properties of the As-prepared catalysts were systematically characterized by various technologies. The catalytic performance was evaluated for hydrogen or syngas production by ethanol steam reforming and methane dry (CO2) reforming, respectively. The results showed that compared with Al2O3 support, the nickel supported on La2O3 possessed a smaller particle size of nickel even after high-temperature reduction. In addition, the La2O3-supported nickel catalyst had stronger metal-support interaction and higher nickel electron density as a result of higher ethanol conversion activity and stability. The ethanol conversion was maintained at 87.8% after a 3000-minute test, and the hydrogen production was as high as 6500 μmol/min. Moreover, the Ni-La2O3 catalyst also showed good activity for methane dry reforming. The initial conversion of methane and carbon dioxide was close to 90%, and the ratio of H2/CO reached 0.94. The better catalytic performance of the Ni-La2O3 catalyst was ascribed to smaller particle size of Ni, rich metal-support interfaces, more nickel electron densities, abundant strong basic sites, and strong metal-support interactions.