Research paperCe0.70La0.20Ni0.10O2-δ catalyst for methane dry reforming: Influence of reduction temperature on the catalytic activity and stability

•Ce0.70La0.20Ni0.10O2-δ, catalyst for methane dry reforming reaction.•Ni-support interactions increase by increasing the reduction temperature; high resistance to carbon deposition.•Apparent specific activity, increases by increasing the nickel particles size.•Reduction at increasing temperature modify the morphology of nickel particles.•Bi-functional mechanism: methane decomposition-carbon removal by Ni-La2O3 interfacial sites as rate determining steps.

The influence of reduction temperature (450-900 °C) on the catalytic activity of Ce0.70La0.20Ni0.10O2-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. H2-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 H2-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, H2-programmed reduction (TPR) and desorption (TPD), CO pulse chemisorption, X-ray photoelectron spectroscopy (XPS) and Scanning Electron Microscopy-Energy dispersive X-Ray (SEM/EDX).

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