Copper doped ceria porous nanostructures towards a highly efficient bifunctional catalyst for carbon monoxide and nitric oxide elimination

Abstract

Copper doped ceria porous nanostructures with a tunable BET surface area were prepared using an efficient and general metal–organic-framework-driven, self-template route. The XRD, SEM and TEM results indicate that Cu²⁺ was successfully substituted into the CeO₂ lattice and well dispersed in the CeO₂:Cu²⁺ nanocrystals. The CeO₂:Cu²⁺ nanocrystals exhibit a superior bifunctional catalytic performance for CO oxidation and selective catalytic reduction of NO. Interestingly, CO oxidation reactivity over the CeO₂:Cu²⁺ nanocrystals was found to be dependent on the Cu²⁺ dopants and BET surface area. By tuning the content of Cu²⁺ and BET surface area through choosing different organic ligands, the 100% conversion temperature of CO over CeO₂:Cu²⁺ nanocrystals obtained from thermolysis of CeCu–BPDC nanocrystals can be decreased to 110 °C. The porous nanomaterials show a high CO conversion rate without any loss in activity even after five cycles. Furthermore, the activity of the catalysts for NO reduction increased with the increase of BET surface, which is in accordance with the results of CO oxidation.