Catalytic performance and characterization of Pd/Ni0.2Mg0.8Al2O4 in oxidative steam reforming of methane under atmospheric and pressurized conditions

Catalytic performance and characterization of Pd/Ni0.2Mg0.8Al2O4 were investigated in oxidative steam reforming of methane under atmospheric and pressurized conditions. Pd/Ni0.2Mg0.8Al2O4 showed much higher methane conversion under high partial pressure of steam, where Ni0.2Mg0.8Al2O4 lost the reforming activity because the Ni species was oxidized under atmospheric pressure. In addition, the addition of Pd on Ni0.2Mg0.8Al2O4 was effective to improve the stability and resistance to coke formation in oxidative steam reforming of methane under pressurized conditions. On the other hand, the formation of Pd–Ni alloy over Pd/Ni0.2Mg0.8Al2O4 was confirmed from the characterization results of TPR, TEM, EXAFS and FTIR, and this can contribute to high catalytic performance of Pd/Ni0.2Mg0.8Al2O4.

Addition of small amount of Pd to Ni0.2Mg0.8Al2O4 enhanced the catalytic activity and stability for the oxidative steam reforming of methane even under the high partial pressure of steam and pressurized conditions, where Ni0.2Mg0.8Al2O4 deactivated due to the oxidation of Ni and carbon deposition. Catalyst characterization results suggest that the formation of Pd–Ni alloy located preferentially on the surface improved the reducibility of Ni and the resistance to the carbon deposition. Figure optionsDownload as PowerPoint slide