The function of Ce in Ni-Ce-Ca@ZrO2 for ICCU-DRM

Ce was added into Ni/Ca@Zr dual functional materials for ICCU-DRM ( As shown in the below figure, NiCe/Ca@Zr showed higher yields of syngas and conversion of CO2 and CH4, compared to Ni/Ca@Zr. Although coke deposition was higher for NiCe/Ca@Zr after 1 cycle of ICCU, the total coke amount after a few cycles was less for NiCe/Ca@Zr, ascribed to be oxidation of carbon during the stage of CO2 capture (carbon and CO2 reaction). Therefore, Ce helps resist coke deposition during ICCU-DRM. XPS analysis also indicated that surface oxygen concentration was reduced after DRM, as lattice oxygen was used for carbon oxidation.


“Integrated CO2 capture and conversion on (A) Ni/Ca@Zr and (B) NiCe/Ca@Zr bifunctional material in ICCU-DRM process: mass spectra of the outlet products during the 1st and 2nd cycles.”


The amount of lattice oxygen was also quantified using O2-TPD (as shown below). NiCe/Ca@Zr showed higher amount of O2 desorption, compared to Ni/Ca@Zr. The O2 desorption peak at 710 C facilitates the availability of the lattice oxygen during the isothermal ICCU cycles. Furthermore, the lattice oxygen of CeO2 could be replenished during the CO2 capture step, by the dissociated of CO2 on the surface of CeO2. Therefore, Ce addition also promoted the activation of CH4, producing more coke. Thus, the presence of Ca is also essential to enhance the performance of Ni/Ce@Zr, regarding the reduction of coke formation.


“O2-TPD for Ni/Ca@Zr and NiCe/Ca@Zr. ” (

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