Anchoring Pt-doped PdO nanoparticles on γ-Al2O3 with highly dispersed La sites to create a methane oxidation catalyst

Abstract

Catalysts for the complete oxidation of methane suffer from poor physical and chemical stability regarding their noble metal active sites. Herein, we prepared a PtPd-La1/Al2O3 catalyst by loading highly dispersed La species and Pt-PdO nanoparticles on γ-Al2O3 support, exhibiting significantly enhanced hydrothermal and long-term stability under the harsh conditions of simulated natural gas vehicle (NGV) exhaust. Over PtPd-La1/Al2O3, PdO nanoparticles (NPs) can be anchored by highly dispersed La sites through electron transfer from La to PdO, inhibiting the sintering of Pd species during hydrothermal aging. Pt uniformly doped in PdO creates high-efficiency Pt sites and unsaturated Pd sites (as well as Pd sites adjacent to O defects) for water-resistance, further enhancing long-term stability. Thus, this work provides the potential to resolve tough challenges related to methane emission control on NGVs.