High activity and selectivity of single palladium atom for oxygen hydrogenation to H 2 O 2 .

Nanosized palladium (Pd)-based catalysts are widely used in the direct hydrogen peroxide (H 2 O 2 ) synthesis from H 2 and O 2 , while its selectivity and yield remain inferior because of the O-O bond cleavage from both the reactant O 2 and the produced H 2 O 2 , which is assumed to have originated from various O 2 adsorption configurations on the Pd nanoparticles. Herein, single Pd atom catalyst with high activity and selectivity is reported. Density functional theory calculations certify that the O-O bond breaking is significantly inhibited on the single Pd atom and the O 2 is easier to be activated to form *OOH, which is a key intermediate for H 2 O 2 synthesis; in addition, H 2 O 2 degradation is shut down. Here, we show single Pd atom catalyst displays a remarkable H 2 O 2 yield of 115 mol/g Pd /h and H 2 O 2 selectivity higher than 99%; while the concentration of H 2 O 2 reaches 1.07 wt.% in a batch.