Bifunctional Pt dual atoms for overall water splitting

While dual-atom catalysts benefiting from synergetic interatomic interactions have inspired the development of emerging catalysts, the role of atomic interactions on the catalytic selectivity and activity has yet to be clearly discovered. Herein, two-types of Pt dual-atom active sites, Pt dimers (2Pt) with an interatomic distance of 2.6 Å and Pt pairs (Pt2) at a distance of 0.9 Å, are fabricated by anchoring onto cationic vacancy-rich nickel-based hydroxide (Pt@NiFeCo-E). It reveals that 2Pt sites are favorable for hydrogen evolution reaction (HER) while Pt2 sites are active towards oxygen evolution reaction (OER). The coexistence of two types of Pt dual atoms endows the bifunctional activity, which reached an overpotential of 14 mV@10 mA cm−2 for HER, an overpotential of 234 mV@100 mA cm−2 for OER, and an effective overall water splitting reaction (OWS) in alkaline at an overpotential of 1.42 V to reach 10 mA cm−2 and at 100 mA cm−2 for 50 h. This work not only clarifies a new mechanism in manipulating the selectivity of dual-atom catalysts via controlling the interatomic distance, but also paves a pathway for designing novel high-efficient bifunctional catalysts.