“…Silica-based materials have also been used (Zhao et al, 2005; Zhu et al, 2005; Xu et al, 2007b, 2008; Li et al, 2009a; Wu et al, 2011a,b,c, 2016b; Wang C. H. et al, 2013; Zhou et al, 2014; Gui et al, 2015; Saxena et al, 2016; Chen L. F. et al, 2017). Au/mesoporous silica showed high catalytic activity and selectivity for cyclohexane oxidation using O 2 in solvent-free conditions (Zhu et al, 2005; Wu et al, 2011a,b,c, 2016b).…”