Comparative study on N2O formation pathways over bulk MoO3 and MoO3-x nanosheets decorated Fe2O3-containing solid waste NH3-SCR catalysts

•MoO3-x nanosheets were prepared by a novel hydrogen peroxide etching method.•The bulk MoO3 and MoO3-x nanosheets both improved the activity of Fe2O3 catalysts.•MoO3-x nanosheets-Fe2O3 exhibited much higher N2 selectivity than bulk MoO3-Fe2O3.•The bulk MoO3 and MoO3-x nanosheets showed disparate NH3 and NO adsorption ability.•The N2O formation pathways via L-H and E-R mechanism were both investigated.