Textual properties and catalytic performances of halloysite hybrid CeO₂-ZrO₂ nanoparticles

Halloysite (Hal) hybridized ceria-zirconia solid solution material (CZ-Hal) for three way catalysis was synthesized through co-precipitation method. X-ray diffraction (XRD), N₂ adsorption-desorption isotherms, transmission electronic microscopy (TEM), scanning electronic microscopy (SEM), X-ray energy dispersion spectrum (EDS), and temperature-programmed H₂ reduction (H₂-TPR) were used to characterize the crystalline, textural, morphological, and reducibility of the products. The three way catalytic performances of the supported products was tested in stoichiometric air/fuel condition. The modified Hal hybridized cerium- zirconium solid solutions showed a rod-like morphology consisted of agglomerated nanoparticles with sizes of about 100nm. The adaption of PEG-4000has guided the formation of the nano-rods in the products. The Hal mineral in the composites retained their tubular morphology. The CZ-Hal composite showed larger BET surface area (130m²/g compared to 71m²/g), concentrated pore size distribution, as well as lower reduction temperature, compared with the pure CZ solid solutions. The supported Pd-Rh/CZ-Hal showed optimized catalytic performances for CO, NO_x (conversion up to 98%), and C_nH_m (70%) at light-off temperatures.