Study On The Selective Catalytic Reduction Of NO_x By Hydrogen Over Pt/TiO₂ Catalyst

In the present paper,the traditional Pt/TiO2 catalyst was modified by two different strategies in order to improve its H2-SCR performance.And a series of characterization methods were used to explore the relationship between the structure of the catalyst and its catalytic performance.The novel Pt/TiO2-D catalyst was synthesized via a sacrificial carbon layer strategy.Modified Pt/TiO2 exhibited an excellent H2-SCR performance with a broad operation temperature window(100-250?).Based on characterization results,it was found the electrons transferred from TiO2 to Pt due to the SMSI effect leading to more Pt species exist in the form of PtO.Furthermore,in situ DRIFTS demonstrated that the SMSI effect not only promoted the adsorption of more active nitrogen-containing species on the catalyst surface,but also significantly improved its reaction rate.Moreover,new intermediate active NHX species were also generated on the modified Pt/TiO2-D catalyst.H2-SCR activity of Pt/TiO2 after treatment under different atmosphere was investigated.The activity test results showed low-temperature de-NOx performance significantly improved after treated in H2.While the Pt/TiO2-O2 catalyst treated in O2 showed similar activity trend as the Pt/TiO2 catalyst.XPS and CO adsorption tests exhibited almost all Pt species on the Pt/TiO2-H2 were reduced to metallic Pt,which is favorable for H2 adsorption and dissociation.In situ infrared analysis showed that the Pt/TiO2-H2 catalyst can adsorb more NOx species,which is of higher reactivity to reacting with H2.