Low-Temperature NOx Reduction by H2 on Mo-Promoted Pt/ZrO2 Catalysts in Lean Exhaust Gases

Abstract This article aims to improve the low-temperature H 2 -deNO x performance of active Pt/ZrO catalyst using MoO as a promoter. For this purpose, systematic series samples were prepared with Pt content 0.25 wt% and Mo loads from 0 10 wt%. The physico-chemically characterized by means powder X-ray diffraction, N physisorption, temperature-programmed desorption CO NH 3 , Raman spectroscopy diffuse reflectance infrared probe molecule, while efficiency was investigated in lean synthetic exhaust. load showed best performance, including between 80 °C 150 °C, maximum NO conversion 90% selectivity up 78%. Isolated species predominately present at below 4 found act structural promoter stabilizing BET surface area, also providing smaller particles more sites, respectively. By contrast, aggregated oxide moieties higher exhibit clearly weaker promotional effect. structure–activity-selectivity correlations suggest that additionally enables SCR-related mechanistic pathway be followed, spill-over sites strong Lewis acid case highly dispersed entities followed reaction .