The Interfacial Effect on H2 Production from Oxidative Steam Reforming of Ethanol Over Rh/Ce1-xLaxO2-δ Nanocatalysts

Abstract

Background: The production of hydrogen from catalytic reforming ethanol has attracted wide attention, which provides a promising way to replace fossil fuels with sustainable energy carriers. Methods: In this work, the Ce1-xLaxO2-δ solid solution (CL) supported Rh catalysts (nRh/CL, n = 0.5, 1 and 2 wt.%) were prepared by a traditional impregnation method with a variation of Rh loading. The different interface structure of nRh/CL catalysts and their catalytic performance in oxidative steam reforming (OSR) reaction were investigated. Results: Rh was loaded by the traditional impregnation method, and ethanol conversion and H2 yield declined in the order of 1%Rh/CL > 2%Rh/CL > 0.5%Rh/CL. Conclusion: The supports of the nRh/CL catalysts were confirmed to be Ce1-xLaxO2-δ solid solution, but only for the 1%Rh/CL catalyst, the Rh species were well-dispersed on the support and formed a Rh2O3//Ce1-xLaxO2-δ interface structure. The super-cell structure of Rh3+-O-RE3/4+ (RE = Ce, La) on the surface of 0.5%Rh/CL catalyst and the formation of interfacial Ce1-x-yLaxRhyO2-δ solid solution for 2%Rh/CL catalyst had effects on the self-activation of the nRh/CL catalysts. The typical lattice expansion of Ce1-xLaxO2-δ solid solution lowered the energy for migration. And the excellent hydrogen and oxygen mobility at the Rh//Ce1-xLaxO2-δ interface for 1%Rh/CL catalyst guaranteed the good catalytic performance for OSR at low temperature.