Abstract
Hydrogen peroxide (H(2)O(2)) is one of the most valuable clean energy sources with a rapidly growing requirement in industry and daily life. The direct synthesis of H(2)O(2) from hydrogen and oxygen is considered to be an economical and environmentally friendly manufacturing route to replace the traditional anthraquinone method, although it remains a formidable challenge owing to low H(2)O(2) selectivity and production. Here, we report a catalyst consisting of Pd(111) nanocrystals on TiO(2) modified with single Pt atoms (Pt(1)Pd(111)/TiO(2)), which displays outstanding reactivity, producing 1921.3 μmol of H(2)O(2), a H(2) conversion of 62.2% and H(2)O(2) selectivity of 80.3% over 30 min. Kinetic and isotope experiments confirm that the extraordinary catalytic properties are due to stronger H(2) activation (the rate-determining step). DFT calculations confirm that Pt(1)Pd(111) exhibits lower energy barriers for H(2) dissociation and two-step O(2) hydrogenation, but higher energy barriers for side reactions than Pt(1)Pd(100), demonstrating clear facet dependence and resulting in greater selectivity and amount of H(2)O(2) produced.