Atomic Heterointerface Boosts the Catalytic Activity toward Oxygen Reduction/Evolution Reaction

Interface engineering is an efficient strategy to enhance the electrocatalytic activity of hybrid materials by taking advantage of the synergistic effect of double or even multiple active sites. Here, the rational design of a Pd/NiO atomic interface with well patterned Pd arrays imbedded into NiO thin films are reported to boost the catalytic activity toward the oxygen reduction/evolution reaction. Theoretical analysis elucidates that the Pd (111)/NiO (111) interface with minimized lattice mismatch effectively adsorbs intermediates (OH*, LiO2*, Li2O2*, and Li2O*) and induces the growth/decomposition of electrochemical reaction products, which greatly lowers the Gibbs energy barrier of crucial steps and boosts the reaction kinetics. As expected, such hybrid thin films exhibit high catalytic activity for both the oxygen reduction reaction and oxygen evolution reaction, with performance comparable to the benchmarked Pt/C and RuO2 catalysts. Moreover, favorable performance is also achieved in both aqueous Zn-air batteries and aprotic Li-air batteries with an overpotential of only 0.69 and 0.50 V, respectively. This work suggests the great potential of such particularly morphological hybrid thin films in the development of high-performance catalysts for energy storage and conversion.