Plasma-engineered Ag/CeO2 catalysts with enhanced surface active oxygen species for catalytic oxidation of VOCs and soot

As primary precursors of particulate matter (PM), volatile organic compounds (VOCs) and soot have emerged as major contributors to air pollution in recent decades. It is urgent and significant to develop high-performance catalysts for the catalytic oxidation of VOCs and soot. In this work, we report a feasible approach for the preparation of Ag-supported CeO 2 catalysts (Ag/CeO 2 -HP) via the combination of impregnation and plasma treatment, and evaluate their performance in catalytic oxidation. Comprehensive characterization results demonstrate that the non-thermal plasma treatment can effectively enhance the dispersion of Ag nanoparticles and enrich the concentration of surface oxygen vacancies in the catalyst. Furthermore, Ag/CeO 2 -HP possesses the highest concentration of the highly surface active oxygen species. Thus, Ag/CeO 2 -HP exhibits the highest catalytic activity for catalytic oxidation of VOCs and soot among all the catalysts prepared. The T max value for soot over Ag/CeO 2 -HP is 383 °C, compared to 409 °C over Ag/CeO 2 prepared by the conventional equivalent-volume impregnation method. Under demanding reaction conditions (1000 ppm hexane, GHSV 75,000 h −1 ), the T 98 values for n-hexane over the Ag/CeO 2 -HP and Ag/CeO 2 catalysts are 295 and 339 °C, respectively. The work provides an efficient strategy to prepare supported catalysts with enhanced catalytic activity.