“…Among these catalysts, V 2 O 5 /TiO 2 in combination with MoO 3 and WO 3 has been commercialized in consequence of its high catalytic reactivity, including NO conversion, N 2 selectivity and resistance to sulfur poisoning, and mechanical strength. In view of high reaction temperature and environmental toxicity of vanadium species (Liu and He, 2010;Liu et al, 2011b;Ma et al, 2011;Youn et al, 2016), vanadium-free catalysts attracted much attention including M-zeolite catalysts (M-Fe, Cu, Mn, Mo) (Pérez-RamıŔez et al, 2004;Yoshida et al, 2004;Liu et al, 2011a;Ochońska et al, 2012;Schuricht and Reschetilowski, 2012;Mejri et al, 2016) and metal oxides catalysts (Fe, Mn, Cu, Ce, Cr, etc. ) (Kato et al, 1981;Baksh et al, 1992;Kapteijn et al, 1994;Chen et al, 1995;Schneider et al, 1995;Zhu et al, 1999;Eigenmann et al, 2006;Min et al, 2007;Xu et al, 2008;Liu et al, 2013a;Shin et al, 2016).…”