Bimetallic MNi/Al2O3-La catalysts (M = Pt, Cu) for acetone steam reforming: Role of M on catalyst structure and activity

The effect of Pt and Cu addition on the behaviour of Ni catalysts supported on Al2O3 modified with La for acetone steam reforming (as model molecule of bio-oil) was studied. Catalytic activity was found to depend strongly on the bimetallic formulation, achieving the bimetallic PtNi catalyst almost complete gasification of the acetone. The characterization results achieved with XRD, TPR and XPS showed differences in surface metal concentrations which depend on the presence of Pt or Cu in catalysts composition. The decrease in activity observed for the bimetallic CuNi catalyst is associated with changes in the acetone reaction mechanism due to the presence of metallic copper since formation of CuNi alloy was not formed in this catalyst. In the case of bimetallic PtNi catalyst, a lower carbon deposition and a higher thermal stability of the Ni crystallites under reaction conditions was observed with respect to monometallic Ni reference catalyst. It is suggested that the better dispersion of metallic nickel crystallites together with the enhanced H-atom mobility on Pt are responsible of the better catalytic behaviour of the bimetallic PtNi formulation in the steam reforming of acetone.This research was supported by the Ministry of Science and Innovation (Spain) and the Autonomous Government of Madrid, Madrid (Spain) under grants ENE2010-21198-C04-01 and S2009ENE-1743, respectively. Partial support to this work came from Najran University, The Kingdom of Saudi Arabia.Peer Reviewe