Enhanced surface properties of CeO2 by MnO doping and their role in mechanism of methane dry reforming deduced by means of in-situ DRIFTS

Abstract MnOx-doped CeO2 and CeO2 supports, and their corresponding catalysts with Ni impregnation were studied in this work. Surface and mechanistic properties of prepared catalysts have been investigated for the process of methane dry reforming with 1:1 pure gas stream. Peak shifts observed in XRD and Raman analyses confirmed the successful incorporation of MnOx into the CeO2 lattice. MnOx doping induces both lattice defects that generate oxygen vacancies, as well as restricts CeO2 crystal growth. TEM elemental mapping evidenced the uniform distribution of Ni on supports. The restriction of crystal growth correspondingly exhibited a huge impact on specific surface area of MnOx-doped catalyst. A possible reaction mechanism has been deduced with the help of in-situ DRIFTS experiments. The oxygen vacancies generated due to the lattice defects in CeO2 played a huge role in enhancing coke resistance. The carbon accumulation reduced from 8.6 to 1.7 wt.% with MnOx doping.