Localized Surface Plasmon Resonance Assisted Photothermal Catalysis of CO and Toluene Oxidation over Pd–CeO₂ Catalyst under Visible Light Irradiation

The extinction peak of Pd particles generally locates at the ultraviolet light region, suggesting that only 4% of solar light can be absorbed. Furthermore, the efficiency of LSPR hot electrons converted to chemical energy of reaction is very low due to the fast relaxation of carriers. It is extremely valuable to design Pd-based catalysts which have strong response to the visible light irradiation and high efficiency in photon to chemical energy. The Pd–CeO₂ catalyst was synthesized via the hexadecyl­trimethyl­ammonium bromide (CTAB) assisted liquid-phase reduction method to generate more active interfaces. The significant extinction of Pd–CeO₂ in the visible to near-infrared region indicates the strong electron interaction between Pd and CeO₂. LSPR hot electrons, transferring from the Pd metal particles to the conduction band of ceria, promote the dissociation of adsorbed oxygen. Therefore, the reaction temperature of CO and toluene oxidation can be significantly lowered by visible light irradiation. The maximum light efficiencies of Pd–CeO₂ catalyst for toluene oxidation and CO oxidation are obtained as 0.42% and 1%, which benefit from the effective Pd–O–Ce interfaces.