Elucidating Ru Distribution State of Ru‐Promoted Pr<sub>2</sub>Sn<sub>2</sub>O<sub>7</sub> Pyrochlore and its Effect on the Catalytic Performance for Toluene Deep Oxidation
Jianjun Liu, Lanling Zeng, Xianglan Xu, Junwei Xu, Xiuzhong Fang, Yijun Bian, Xiang Wang
Abstract
Abstract To obtain applicable catalysts for toluene combustion, Ru‐promoted Pr 2 Sn 2 O 7 has been prepared with impregnation (Ru/Pr 2 Sn 2 O 7 ) and hydrothermal method (Ru−Pr 2 Sn 2 O 7 ). For the two Ru/Pr 2 Sn 2 O 7 catalysts, Ru scatters on the surface of Pr 2 Sn 2 O 7 as both metallic Ru and RuO 2 . In contrast, for the two Ru−Pr 2 Sn 2 O 7 catalysts, Ru is substituted into Pr 2 Sn 2 O 7 lattice as Ru 4+ . The distribution states of Ru affect significantly the active surface oxygen amount and the toluene adsorption capacity, which are the two major reasons influencing the reactivity. On Ru/Pr 2 Sn 2 O 7 , a greater quantity of active oxygen sites can be formed than on Ru−Pr 2 Sn 2 O 7 . Furthermore, the presence of surface Ru 0 facilitates also toluene adsorption. As a consequence, the intrinsic activity of the two Ru/Pr 2 Sn 2 O 7 catalysts are much higher than the two Ru−Pr 2 Sn 2 O 7 catalysts . It is concluded that supporting Ru on Pr 2 Sn 2 O 7 surface is a better way than doping Ru into its lattice to fabricate more active and applicable catalysts.