Abstract
Nitrogen oxide (NO(x)) pollution presents a severe threat to the environment and human health. Catalytic reduction of NO(x) with H(2) using single-atom catalysts poses considerable potential in the remediation of air pollution; however, the unfavorable process of H(2) dissociation limits its practical application. Herein, we report that the in situ formation of Pt(Ti) cocatalytic sites (which are stabilized by Pt-Ti bonds) over Pt(1)/TiO(2) significantly increases NO(x) conversion by reducing the energy barrier of H(2) activation. We demonstrate that two H atoms of H(2) molecule are absorbed by adjacent Pt atoms in Pt-O and Pt-Ti, respectively, which can promote the cleave of H-H bonds. Besides, Pt(Ti) sites facilitate the adsorption of NO molecules and further lower the activation barrier of the whole de-NO(x) reaction. Extending the concept to Pt(1)/Nb(2)O(5) and Pd(1)/TiO(2) systems also sees enhanced catalytic activities, demonstrating that engineering the cocatalytic sites can be a general strategy for the design of high-efficiency catalysts that can benefit environmental sustainability.