Effect of Sn addition on the catalytic performance of a Pd–Cu/attapulgite catalyst for room-temperature CO oxidation under moisture-rich conditions

Abstract

Herein, the effect of SnCl₄ addition on the catalytic performance of Pd–Cu/attapulgite (Pd–Cu/APT) synthesized by a deposition–precipitation method has been investigated. Compared with Pd–Cu/APT, the suitable addition of Sn has a conspicuous facilitation on the catalytic performance of Pd–Cu–Sn/APT for CO oxidation. The characterization results reveal that the incorporation of Sn gives rise to the formation of SnO₂, which conduces to produce the more Cu₂Cl(OH)₃ active phases and Cu⁺ species in Pd–Cu–Sn/APT and establish a mutual interaction between Sn and Pd, Cu species. Accordingly, the Pd⁰ species generated during CO oxidation over Pd–Cu–Sn/APT can be more easily oxidized than those over Pd–Cu/APT. Additionally, the generation of SnO₂ is prone to suppress the adsorption of water vapor on the catalyst surface, hence augmenting the water resistance of Pd–Cu–Sn/APT. Therefore, Sn-modified Pd–Cu/APT catalyst exhibits the more excellent catalytic performance for CO oxidation at room temperature under moisture-rich conditions.