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

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 Pd-0 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.