Optimizing the Pd Sites in Pure Metallic Aerogels for Efficient Electrocatalytic H₂O₂ Production

Abstract

Decentralized electrochemical production of hydrogen peroxide (H2O2) 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, a novel catalyst design strategy is reported 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 Pd2Hg5 aerogel. Further heterometal doping leads to a series of M–Pd2Hg5 aerogels with an unalterable geometric environment, allowing for sole investigation of the electronic effects. Combining theoretical and experimental analyses, a volcano relationship is obtained for the M–Pd2Hg5 aerogels, demonstrating an effective tunability of the electronic structure of the Pd active sites. The optimized Au–Pd2Hg5 aerogel exhibits an outstanding H2O2 selectivity of 92.8% as well as transferred electron numbers of ≈2.1 in the potential range of 0.0–0.4 VRHE. This work opens a door for designing metallic aerogel electrocatalysts for H2O2 production and highlights the importance of electronic effects in tuning electrocatalytic performances.

WO3‐Assisted Synergetic Effect Catalyzes Efficient and CO‐Tolerant Hydrogen Oxidation for PEMFCs

“…Fringe lattices of both WO 3 and Pd can be observed (Figure 2h), in which the lattice spacing of 0.38 nm corresponds to (001) lattice of orthorhombic WO 3 , and that of 0.22 nm is assigned to the (111) plane of Pd. [ 17 ] The average particle sizes of Pd follow the order of 3Pd‐WO 3 /C > 2Pd‐WO 3 /C > 1Pd‐WO 3 /C > 4Pd‐WO 3 /C (Figure 2c,f,i,l). Carbon matrix plays an important role in preventing the aggregation of Pd and WO 3 components, which maintains the homogeneous nanoparticle distributions of ≈2–3 nm in average size, ensuring the catalytic activity and stability.…”

Ni clusters immobilized on oxygen-rich siloxene nanosheets for efficient electrocatalytic oxygen reduction toward H2O2 synthesis

“…3,4 However, this traditional approach not only results in significant energy consumption, but also generates a substantial amount of difficult-to-manage organic waste. [5][6][7][8] Furthermore, the complex purification and separation processes involved in the production, as well as the centralized transportation and storage of H 2 O 2 , continue to pose significant hazards and present formidable challenges. 9,10 Therefore, developing a cost-effective H 2 O 2 production technology has become particularly crucial.…”

Modular Iron–Bipyridine-Based Conjugated Aerogels as Catalysts for Oxygen Reduction Reaction

“…Covalent organic frameworks (COFs) in the form of aerogels offer many merits that make them very interesting platforms for PGM-free ORR catalysts. , By tailoring their building blocks, the catalyst can be embedded into the support synthetically instead of being added onto the support . This allows improved control over both the chemical structure and the active site density, increasing metal utilization and improving mass transport. − In addition, the physical and chemical properties can be tuned to optimize these aerogels for the best performance in FCs. These highly porous hierarchical structures are usually heat treated to improve their electronic conductivity , to be used as catalyst supports.…”