A New Strategy for Improving the Efficiency of Low-temperature Selective Catalytic Reduction of NOx with CH4via the Combination of Non-thermal Plasma and Ag2O/TiO2 Photocatalyst

In the present work,a remarkable combination of non-thermal plasma and photocatalyst was developed to widen the operating temperature window of selective catalytic reduction(SCR)of NOx with CH4,especially to improve the low-temperature removal efficiency of NOx.It was shown that the operating temperature window was significantly widened.Among all the catalysts prepared,1%Ag2O/TiO2 showed the highest catalytic activity for NOx removal due to the utilization of near ultraviolet light.The conversion of NOx to N2 over the in-plasma 1%Ag2O/TiO2 photocatalyst at 60 and 300℃ could achieve 31.8%and 53.0%,respectively.The combination mode of plasma and catalyst affected NOx removal efficiency greatly,the in-plasma catalysis outperformed the post-plasma catalytic mode remarkably,signifying the contribution of photocatalytic processes on the catalysts.Meanwhile,the characterizations of the catalyst demonstrated that the morphology and structure of the Ag2O/TiO2 catalyst were unchanged throughout the non-thermal plasma and photocatalytic processes,implying the superior stability of the catalyst.