Catalytic performance of a Pt-Rh/CeO2-ZrO2-La2O3-Nd2O3 three-way compress nature gas catalyst prepared by a modified double-solvent method

A Pt-Rh three-way catalyst (M-DS) supported on CeO2-ZrO2-La2O3-Nd2O3 and its analogous supported catalyst (DS) were developed via a modified double-solvent method and conventional double-solvent method, respectively. The as-prepared catalysts were characterized by N-2 adsorption-desorption, X-ray diffraction (XRD), CO-chemisorption, X-ray photoelectron spectroscopy (XPS) and hydrogen temperature-programmed reduction (H-2-TPR). The preformed Pt nanoparticles generated using ethanol as a reducing agent on M-DS presented enhanced Pt dispersion regardless of aging treatment as confirmed by XRD and CO-chemisorption measurements. The textural properties and reduction ability of M-DS were maintained to a large extent after aging treatment. This result was consistent with those of the N2 adsorption-desorption and H-2-TPR, respectively. Meanwhile, the XPS analysis demonstrated that higher Pt-0 species and larger Ce3+ concentration could be obtained for M-DS. In the conversion of a simulated compressed natural gas (CNG) vehicle exhaust, both fresh and aged M-DS showed a significant enhancement in the activity and N-2-selectivity. Particularly, the complete conversion temperature (T-90) of CH4 over the aged M-DS catalyst was 65 degrees C lower than that over the aged catalyst by conventional double-solvent method.