Boron-doped graphene nanosheet-supported Pt: a highly active and selective catalyst for low temperature H2-SCR

Abstract

A series of boron-doped graphene-supported Pt (Pt/BG) nanosheets were designed and synthesized using a one-step facile hydrothermal method. ICP, XPS, and TPD results confirmed that boron atoms were successfully embedded into the graphene matrix. The selective catalytic reduction of nitric oxide with hydrogen (H₂-SCR) was tested over Pt/BG catalysts. The multi-roles of doped-boron were investigated by Raman, BET, CO-chemisorption, H₂-TPD, XPS, and NO-TPD. Boron doping led to a higher dispersion and smaller size of Pt nanoparticles, facilitated hydrogen spillover, promoted more metallic Pt formation, and increased both H₂ and NO chemisorption, which were attributed to an enhanced Pt nucleation rate over doped-boron, electron donation from boron to Pt, and extra chemisorption sites. The reaction performances (conversion 94.7%, selectivity 90.3%, and TOF 0.092 s⁻¹) were greatly promoted attributing to a bifunctional catalytic mechanism. This work paves the way to modify the structure and tune the chemisorption ability of graphene-based catalysts, and provides novel insights for designing high performance catalysts.