Ce0.70La0.20Ni0.10O2-δ catalyst for methane dry reforming: Influence of reduction temperature on the catalytic activity and stability

Abstract The influence of reduction temperature (450–900 °C) on the catalytic activity of Ce 0.70 La 0.20 Ni 0.10 O 2-δ sample during methane dry reforming reaction to synthesis gas has been studied. The activity of the sample, prepared by combustion synthesis, has been evaluated at 750 °C under increasing gas hourly space velocity (from 26400 to 105600 h −1 ) for 50 h of stream. H 2 -reduction of the sample at 450 °C induces, during reaction, large amount of carbon deposition (21–27%) that increases by increasing the gas hourly space velocity (GHSV), as revealed by TPO analysis on spent catalysts. Stable activity was revealed after reduction at 750 and 900 °C under a GHSV of 26400 h −1 . The catalytic activity of the reduced samples, by apparent specific activity, increases by increasing the Ni particles size and by increasing the fraction of Ni sites revealed by H 2 -TPD peak at high temperature. The catalytic behavior has been discussed on the basis of the samples characterizations derived from X-ray diffraction, UV–vis diffuse reflectance spectroscopy, H 2 -programmed reduction (TPR) and desorption (TPD), CO pulse chemisorption, X-ray photoelectron spectroscopy (XPS) and Scanning Electron Microscopy-Energy dispersive X-Ray (SEM/EDX).