Nanoshaped Cerium Oxide with Nickel as a Non-Noble Metal Catalyst for CO(2) Thermochemical Reactions

Four different nanoshapes of cerium dioxide have been prepared (polycrystals, rods, cubes, and octahedra) and have been decorated with different metals (Ru, Pd, Au, Pt, Cu, and Ni) by incipient wetness impregnation (IWI) and ball milling (BM) methods. After an initial analysis based on oxygen consumption from CO(2) pulse chemisorption, Ni-like metal, and two forms of CeO(2) cubes and rods were selected for further research. Catalysts were characterized using the Brunauer-Emmett-Teller formula (BET), X-ray spectroscopy (XRD), Raman spectroscopy, scanning electron microscopy (SEM), UV–visible spectrophotometry (UV-Vis), X-ray photoelectron spectroscopy (XPS), temperature programmed reduction (H(2)-TPR) and CO(2) pulse chemisorption, and used to reduce of CO(2) into CO (CO(2) splitting). Adding metals to cerium dioxide enhanced the ability of CeO(2) to release oxygen and concomitant reactivity toward the reduction of CO(2). The effect of the metal precursor and concentration were evaluated. The highest CO(2) splitting value was achieved for 2% Ni/CeO(2)-rods prepared by ball milling using Ni nitrate (412 µmol/g(cat)) and the H(2) consumption (453.2 µmol/g(cat)) confirms the good redox ability of this catalyst.