Self-assembly preparation of Au/SiO2 catalyst and its catalysis for cyclohexane oxidation with air

Abstract

Au/SiO 2 catalysts were prepared by self-assembly technique and characterized by EDS, XRD, XPS, AAS and N 2 adsorption/desorption. They were found to be very efficient catalysts for the selective oxidation of cyclohexane with air in the absence of any solvent or promoter. The influences of Au loading, reaction temperature, reaction pressure and reaction time on the catalytic activity were explored in detail. Under suitable reaction conditions, the conversion of cyclohexane and total selectivity of cyclohexanone and cyclohexanol were up to *10 and *92%, respectively.

Supported Gold Nanoparticles as Catalysts for the Oxidation of Alcohols and Alkanes

“…Metal oxides have also been referred as supports for Au for the same reaction (Zhu et al, 2005; Xu et al, 2007a,b, 2008; Carneiro et al, 2009, 2011; Li et al, 2009a,b; Xie et al, 2009, 2011; Hereijgers and Weckhuysen, 2010; Wu P. P. et al, 2010; Wan et al, 2011; Wu et al, 2011a,b,c, 2016b; Alshammari et al, 2012, 2015, 2016; Conte et al, 2012; Sun et al, 2012; Sannino et al, 2013; Wang C. H. et al, 2013; Zhou et al, 2014; Gui et al, 2015; Liu et al, 2015; Mohamed, 2015; Chen L. F. et al, 2017; Martins et al, 2017). Most studies were carried out using O 2 as oxidant (Zhu et al, 2005; Xu et al, 2007a,b, 2008; Li et al, 2009a; Xie et al, 2009, 2011; Hereijgers and Weckhuysen, 2010; Wu P. P. et al, 2010; Wan et al, 2011; Wu et al, 2011a,b,c, 2016b; Alshammari et al, 2012; Sun et al, 2012; Wang C. H. et al, 2013; Zhou et al, 2014; Gui et al, 2015; Chen L. F. et al, 2017). Many reports refer the use of TiO 2 based materials (Carneiro et al, 2009, 2011; Hereijgers and Weckhuysen, 2010; Alshammari et al, 2012; Sun et al, 2012; Sannino et al, 2013; Zhou et al, 2014; Martins et al, 2017).…”

Direct oxidation of cyclohexane to adipic acid using nano-gold catalysts

“…Furthermore, efforts were also made by various researchers to use gold-based catalysts for the direct oxidation of CH to AA, but to the best of our knowledge, all such attempts went unsuccessful until now. For instance, various gold catalysts such as Au/graphite, Au/MCM-41 [8], Au/SBA-15, and SiO 2 [9] supports were applied for the said reaction, which gave only cyclohexanol and cyclohexanone as major products without any adipic acid in the product stream. Using such catalyst systems, the conversion of CH was varied in the range from 6 to 20 %, but almost no formation of adipic acid was reported.…”