Steam reforming of hydrocarbons from biomass-derived syngas over MgAl 2 O 4 -supported transition metals and bimetallic IrNi catalysts

•Steam reforming of biomass-derived syngas.•Promoting Ni catalyst with Ir significantly enhances stability for the steam reforming of tars.•IrNi catalysts offer more stability than Ir particles alone.•A superior activity for the bimetallic IrNi catalyst as compared to the monometallic Ir and Ni catalysts when normalized per site number.