Supported-induced effect on the catalytic properties of Rh and Pt-Rh particles deposited on La2O3 and mixed α-Al2O3-La2O3 in the dry reforming of methane

Abstract Rhodium and platinum-rhodium based catalysts supported on La 2 O 3 and Al 2 O 3 doped with La 2 O 3 were investigated in the dry reforming of methane. The textural and structural properties were studied on calcined, reduced and used catalysts from nitrogen physisorption, X-ray diffraction, XPS, SEM, H 2 - and O 2 -temperature-programmed experiments. Rh is intrinsically more active than Pt independently of the support composition. Different types of interactions occur when Rh is incorporated in Pt on La 2 O 3 and La-modified α-Al 2 O 3 supports with the observations of synergistic effects on the activity of Pt-Rh/Al 2 O 3 -La 2 O 3 for methane conversion. Correlations between catalytic properties with structural and surface properties have been tentatively established and are discussed. A detrimental effect of alloyed Pt-Rh particles on La 2 O 3 and a beneficial effect on the catalytic activity of Pt-Rh/Al 2 O 3 -La 2 O 3 due to the formation of possible composite microstructures combining noble metals and the elements of the support is reported.