Synergistic degradation of NO and ethyl acetate by plasma activated “pseudo photocatalysis” on Ce/ZnGa2O4/NH2-UiO-66 catalyst: Restrictive relation and reaction pathways exploration

Abstract

• In plasma, NO 2 inhibited the mineralization of EA, centered on C 3 H 6 O. • Ce/ZnGa 2 O 4 enhanced the reaction rate of NO and EA removal. • NH 2 -UiO-66 further decoration facilitated NO 2 deep-oxidation and EA mineralization. • The catalysts prioritized the generation of C 2 H 4 O, the key intermediate of EA. This study developed synergistic control of NO and ethyl acetate (EA) in plasma system. There existed restrictive relation between NO x and EA when co-degraded in plasma. NO 2 inhibited EA degradation especially its mineralization, due to the “fast NO x reaction”. For breaking this restriction, Ce/ZnGa 2 O 4 /NH 2 -UiO-66 catalyst was designed and form “plasma-catalysis” hybrid system. Under the plasma induced “pseudo photocatalysis”, there was 100% and 96.21% NO and EA removal efficiency, respectively, at SIE of 392 J/L, where the selectivity of CO 2 and CO x was 73.93% and 94.35%, respectively. Intermediate analysis indicated that NO 2 mainly suppressed the mineralization of C 3 H 6 O, whilst the addition of catalysts accelerated the formation of C 2 H 4 O, the key intermediate. The enhanced performance was attributed to the improved yield of active radicals, the good adsorption ability and activation of EA and NO x , and the hydrolysis of EA. Radicals (·O 2 – and ·OH) both participated in the reactions, in which ·O 2 – was dominating. The clarity of the restrictive relation between NO x and VOCs in plasma may provide guidance for further studies. The catalyst design strategy is likely to inspire more artful catalysts for plasma-catalysis systems.