High‐Pressure Ethanol Steam Reforming on Ni/Al2O3: Effect of Basic Metal Oxide Modification

Abstract Compared to atmospheric pressure, ethanol steam reforming (ESR) at high pressure is more attractive for large‐scale hydrogen production due to lower energy losses and facility costs but usually suffers from a high potential to methanation side‐reaction. Therefore, manufacture of suitable catalyst that suppressing the formation of methane at high‐pressure remains a great challenge. In this work, a series of NiM/Al 2 O 3 (M = Mg, La, and K) catalysts modified by basic metal oxide were prepared and applied in high‐pressure ESR reaction. Compared with bare Ni/Al 2 O 3 , it was found that the introduction of basic metal oxides can significantly inhibit the formation of methane and improve hydrogen production. Among these catalysts, the sample modified with 5% K displayed the best performance, which enabled a reduction of methane formation by 67.1% and gave a hydrogen production rate reaching 0.65 mol/g cat. /h with excellent stability within 60 h at 400 °C. The characterization results showed that K‐doping could reduce the acidity sites of catalyst and increase the electron density over Ni 0 . As a result, the side reaction of methanation was greatly suppressed with enhanced hydrogen production, thereby improving the high‐pressure ESR performance over Ni 15 K 5 /Al 2 O 3 .