高Au利用率Au^Cu纳米复合催化剂的制备与表征

his work attempted to construct Au-on-Cu nanostructured catalysts (coded as Aum^Cu, and Au/Cu atomic ratio m = 0.1, 0.3 and 0.5) by reductively depositing Au with different amounts on Cu nanoparticles (~3.6 nm), and the catalytic performance of samples was investigated by hydrogenation of p-nitrophenol to p-aminophenol. The signal of Cu in UV-vis spectra was decreased and the size of sample particles monitored by TEM was increased with the increase of m of samples, disclosing that Au was reductively deposited on the surface of Cu nanoparticles, i.e., Aum^Cu nanostuctured samples have been successfully prepared, meanwhile, the size of Au deposits on the surface of particles was decreased or the dispersion of Au could be increased by controllably decreasing m of samples. Comparing the turnover numbers which normalizes the mass of Au in samples (TONAu), we found that TONAu was increased when decreasing m of samples, and the TONAu on Au0.1^Cu catalyst was increased at least by 10 times that on traditional pure Au catalysts. These results suggest that mass specific activity, i.e., the utilization of Au catalyst can be dramatically enhanced by depositing Au on Cu nanoparticles to construct Au^Cu nanostructure, which also suggests that by deliberately distributing precious metals on other metal nanoparticles to construct metal nanocomposites, it would be hopeful to obtain precious metal thermal-catalysts with high utilization.