The effect of Ni-Mg particle size on product selectivity, catalyst activity and coke formation on Ni/MgO/α-Al2O3 catalyst were studied in simultaneous steam and CO2 reforming of methane to syngas. The Ni-Mg particle sizes in the range of 13.7 to 29.7 nm were prepared via incipient wetness impregnation method using α-Al2O3 as support. Experimental results for turn over frequency (TOF) show that the intrinsic catalyst performances were dependent on Ni-Mg particle size. However, the products selectivities and H2/CO ration were found to be independent of Ni-Mg particle size. The experimental results reveal that the coke formation rates on the surface of catalysts are increased by increasing Ni-Mg particle size. Nevertheless, the correlated site carbon atom deposition rates (carbon atoms deposited on one site of catalyst) is shown an opposite trend.

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