Promoting the Direct H 2 O 2 Generation Catalysis by Using Hollow Pd-Sn Intermetallic Nanoparticles.

Although direct hydrogen (H2 ) oxidation to hydrogen peroxide (H2 O2 ) is considered as a promising strategy for direct H2 O2 synthesis, the desirable conversion efficiency remains formidable challenge. Herein, highly active and selective direct H2 oxidation to H2 O2 is achieved by using hollow Pd-Sn intermetallic nanoparticles (NPs) as the catalysts. By tuning the catalytic solvents and catalyst supports, the efficiency of direct H2 oxidation to H2 O2 can be optimized well with the hollow Pd2 Sn NPs/P25 exhibiting H2 O2 selectivity up to 80.7% and productivity of 60.8 mol kgcat -1 h-1 . In situ diffuse reflectance infrared Fourier transform spectroscopy of CO adsorption results confirm the different surface atom arrangements between solid and hollow Pd-Sn NPs. X-ray photoelectron spectra results show that the higher efficiency of Pd2 Sn NPs/P25 is due to its higher content of metallic Pd and higher ratio of Snx + , which benefit H2 O2 production and selectivity.