Hydrogen production from bio-ethanol on rhodium based catalysts

The influence of metal precursor on the catalytic behaviour of Rh/MgO catalysts in the steam reforming of ethanol was investigated. High dispersed catalysts were obtained in the case of use an inorganic precursor like Rh-nitrate. Catalytic tests performed at molten carbonate fuel cell (MCFC) operative conditions (TR = 923 K) clearly shown that reaction under study is a structure sensitive reaction since the turnover frequency (TOF) significantly increases as the Rh mean particle size increases too. Catalysts prepared by using Rh-acethyl-acetonate as precursor shown a higher stability since they are in general less affected by coke formation. Thermodynamic consideration made on the basis of the outlet composition of reaction stream, allowed to calculate the experimental equilibrium constant (Kexp) for i) methane steam reforming (MSR) , ii) water gas shift (WGS), iii) methane pyrolisys and iv) Bouduard reactions.