Ni-exsolved PrBaMn2-xNixO6-δ–based catalysts for high performance of ethanol steam reforming

Abstract

PrBaMn2O6-δ (PBMO) and PrBaMn2-xNixO6-δ (PBMNO) with exsolved Ni nanoparticles (1.25 wt.%, Ni-PBMNO) are prepared for the development of high-performance catalysts for ethanol steam reforming (ESR). The activity of Ni-PBMNO increases with temperature and is higher than that of PBMO. At 600 °C, Ni-PBMNO demonstrates an ethanol conversion above 90%, an H2–CO yield about 80%, and a negligible amount of CH4. Both Ni-PBMNO and PBMO remain unchanged structurally in dry and wet N2. The former adsorbs more H2O than the latter by forming hydroxyl groups in the lattice because of its higher concentration of oxygen vacancy caused by Ni exsolution, rendering a coking resistance one to two orders higher than conventional catalysts. In the ESR atmosphere, the PBMNO substrate decomposes increasingly without lowering ESR activity. The co-existence of CO2 and H2O is necessary for the decomposition that formed BaCO3 and MnO.