Hydrogen production by methane decomposition and catalytic partial oxidation of methane over Pt/CexGd1 − xO2 and Pt/CexZr1 − xO2

Hydrogen production by methane decomposition and catalytic partial oxidation of methane (CPOM) over Pt/(Ce0.91Gd0.09)O2 − x and Pt/(Ce0.56Zr0.44)O2 − x were studied. Results show that during the methane decomposition tests, in the absence of gaseous oxygen, hydrogen and CO were the main products and very small quantities of CO2 were recorded. The generation of these products lasted for about 2 h, indicating that in the catalytic stability of these materials, the carrier plays an important factor. The addition of Gd and Zr cations to ceria had a positive effect on the catalysts stability. Regarding the catalytic partial oxidation of methane, a stable hydrogen production was recorded for 20 h. Here, it is proposed that the formation of a Pt-O-Ce bond causes high stability of Pt in Ce-containing supports under oxidizing conditions at high temperatures because this bond may act as an anchor, inhibiting the sintering of Pt. The deposited carbon during the catalytic tests was oxidized and the CO2 profiles showed a sharper peak appearing at a lower temperature and a broader peak at the higher temperature. The first peak may correspond to the oxidation of coke on and in the vicinity of the metal and the second CO2 peak may represent the coke on the carrier. The CPOM as a function of O/C ratio was studied. It was observed that the catalyst with a higher ionic conductivity, Pt/(Ce0.91Gd0.09)O2 − x, generated a lower amount of deposited carbon.