Ru−FeNi Alloy Heterojunctions on Lignin‐derived Carbon as Bifunctional Electrocatalysts for Efficient Overall Water Splitting

• Published in: Angewandte Chemie International Edition 2023-08, Vol.62 (33), p.e202306333-n/a
• Main Authors: Lin, Xuliang, Liu, Jianglin, Qiu, Xueqing, Liu, Bowen, Wang, Xiaofei, Chen, Liheng, Qin, Yanlin
• Format: Article
• Language: English
• Subjects: Bifunctional Electrocatalysts; Carbon; Catalysts; Electrocatalysts; Electron transfer; Electronic structure; Free energy; Green hydrogen; Heterojunction; Heterojunctions; Hydrogen evolution reactions; Hydrogen production; Intermediates; Intermetallic compounds; Lignin; Lignin-Derived Carbon; Nanoalloys; Nanoparticles; Oxygen evolution reactions; Pyrolysis; Reaction kinetics; Ruthenium; Self-assembly; Splitting; Water Splitting
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202306333

Rational design of efficient, stable, and inexpensive bifunctional electrocatalysts for oxygen evolution reactions (OER) and hydrogen evolution reactions (HER) is a key challenge to realize green hydrogen production via electrolytic water splitting. Herein, Ru nanoparticles and FeNi alloy heterojunction catalyst (Ru−FeNi@NLC) encapsulated via lignin‐derived carbon was prepared by self‐assembly precipitation and in situ pyrolysis. The designed catalyst displays excellent performance at 10 mA cm−2 with low overpotentials of 36 mV for HER and 198 mV for OER, and only needs 1.48 V for overall water splitting. Results and DFT calculations show the unique N‐doped lignin‐derived carbon layer and Ru−FeNi heterojunction contribute to optimized electronic structure for enhancing electron transfer, balanced free energy of reactants and intermediates in the sorption/desorption process, and significantly reduced reaction energy barrier for the HER and OER rate‐determining steps, thus improved reaction kinetics. This work provides a new in situ pyrolysis doping strategy based on renewable biomass for the construction of highly active, stable and cost‐effective catalysts. Here, a novel lignin‐derived carbon‐supported Ru−FeNi@NLC heterojunction catalyst for water electrolysis was proposed. The synergistic interaction between the heterogeneous structure and the lignin‐derived carbon layer produced a total water decomposition interface adjustment of 10 mA cm−2 at 1.48 V, which reduced the energy barrier and improved the reaction kinetics of oxygen evolution and hydrogen evolution reactions.