Optimizing the Pd Sites in Pure Metallic Aerogels for Efficient Electrocatalytic H 2 O 2 Production.

Decentralized electrochemical production of H 2 O 2 is an attractive alternative to the industrial anthraquinone process, the application of which is hindered by the lack of high-performance electrocatalysts in acidic media. Herein, we report a novel catalyst design strategy to optimize the Pd sites in pure metallic aerogels by tuning their geometric environments and electronic structures. By increasing the Hg content in the Pd-Hg aerogels, the Pd-Pd coordination is gradually diminished, resulting in isolated, single-atom-like Pd motifs in the Pd 2 Hg 5 aerogel. Further heterometal doping leads to a series of M-Pd 2 Hg 5 aerogels with an unalterable geometric environment, which allows us to solely investigate the electronic effects. Combining theoretical and experimental analysis, a volcano relationship has been obtained for the M-Pd 2 Hg 5 aerogels, demonstrating an effective tunability of the electronic structure of the Pd active sites. The optimized Au-Pd 2 Hg 5 aerogel exhibits an outstanding H 2 O 2 selectivity of 92.8% as well as transferred electron numbers of ∼2.1 in the potential range of 0.0 - 0.4 V RHE . Our work opens a door for designing metallic aerogel electrocatalysts for H 2 O 2 production and highlights the importance of electronic effects in tuning electrocatalytic performances. This article is protected by copyright. All rights reserved.