Nickel-based ceria, zirconia, and ceria-zirconia catalytic systems for low-temperature carbon dioxide reforming of methane

Carbon dioxide reforming of methane (CDRM) was studied over a variety of ZrO2-, ceria-doped ZrO2-, and CeO2-ZrO2-supported Ni catalysts. Different techniques were used to prepare supports material having different physicochemical properties, and a correlation was established to show the importance of a robust support material. Various characterization of the catalyst further established that the coking behavior of the catalyst depends on the support preparation techniques. Compared to zirconia and ceria-doped zirconia, the use of ceria-zirconia (CexZr1-xO2) solid solution as a support prepared by using a surfactant was found to be the most stable for low-temperature CDRM. It seems the inhibition of reactions leading to carbon deposition is prominent in system having ZrO2. Temperature-programmed oxidation (TPO) experiments indicated excellent resistance toward carbon formation for Ni supported on CexZr1-xO2 compared with other catalysts studied. H-2-TPR (temperature-programmed reduction) analyses also showed that the stability of Ce-x,Zr1-xO2 solid solution is a function of its enhanced reducibility at lower temperatures as compared to either pure ceria or ceria-doped ZrO2. Based on all the catalysts studied, 5% Ni Ce0.6Zr0.4O2 was found to be the best catalyst as activity was stable for up to 100 It at 650 and 700 degrees C, while at 800 degrees C the catalyst activity remained stable for more than 200 h.