p‐Block Bismuth Nanoclusters Sites Activated by Atomically Dispersed Bismuth for Tandem Boosting Electrocatalytic Hydrogen Peroxide Production

Abstract Constructing electrocatalysts with p ‐block elements is generally considered rather challenging owing to their closed d shells. Here for the first time, we present a p ‐block‐element bismuth‐based (Bi‐based) catalyst with the co‐existence of single‐atomic Bi sites coordinated with oxygen (O) and sulfur (S) atoms and Bi nanoclusters (Bi clu ) (collectively denoted as BiOS SA /Bi clu ) for the highly selective oxygen reduction reaction (ORR) into hydrogen peroxide (H 2 O 2 ). As a result, BiOS SA /Bi clu gives a high H 2 O 2 selectivity of 95 % in rotating ring‐disk electrode, and a large current density of 36 mA cm −2 at 0.15 V vs. RHE, a considerable H 2 O 2 yield of 11.5 mg cm −2 h −1 with high H 2 O 2 Faraday efficiency of ∼90 % at 0.3 V vs. RHE and a long‐term durability of ∼22 h in H‐cell test. Interestingly, the experimental data on site poisoning and theoretical calculations both revealed that, for BiOS SA /Bi clu , the catalytic active sites are on the Bi clusters, which are further activated by the atomically dispersed Bi coordinated with O and S atoms. This work demonstrates a new synergistic tandem strategy for advanced p ‐block‐element Bi catalysts featuring atomic‐level catalytic sites, and the great potential of rational material design for constructing highly active electrocatalysts based on p ‐block metals.