Lignin-mediated atomic coordination engineering of Ru nanoclusters with self-optimized Mott-Schottky interfaces for industrial hydrogen production
Jianglin Liu, Bowen Liu, Xiaofei Wang, Yanlin Qin, Jason Chun‐Ho Lam, Xuliang Lin, Xueqing Qiu
Abstract
The global transition toward carbon neutrality urgently demands scalable green hydrogen technologies driven by renewable energy. While water electrolysis represents a key pathway, current anion exchange membrane technologies face critical limitations in catalyst stability and efficiency, particularly in terms of ruthenium-based cathodes for the alkaline hydrogen evolution reaction (HER). Conventional synthesis methods frequently encounter irreversible nanoparticle aggregation due to weak metal-ligand coordination, significantly compromising catalytic durability. We present a groundbreaking supramolecular assembly strategy utilizing lignin's polyphenolic architecture to construct robust lignin-metal supramolecular framework complexes (MSF@Lignin), achieving unparalleled dispersion of Ru active sites. Subsequent pyrolysis induces synergistic structural coupling between carbonized lignin matrices and Ru nanoclusters, forming electron-redistributed Mott-Schottky interfaces that drastically enhance charge transfer kinetics. The anion exchange membrane-water electrolyzer (AEMWE) device using Ru@OALC as the cathode achieved an industrial-grade current density of 0.5 A cm −2 at an extremely low cell voltage of 1.69 V at 25°C and operated stably for 800 h at a slow voltage decay of 0.1 mV h −1 . We elucidate the structure-activity relationship of Ru@OALC. In situ monitoring of adsorption effects during HER reaction by electrochemical quartz crystal microbalance (EQCM) was proposed for the first time, and the dissociation of H 2 O molecules was visualized as a rate-limiting step for alkaline HER. This research underscores lignin’s potential in developing stable electrocatalysts, advancing electrocatalytic materials, and contributing to sustainable hydrogen production for a cleaner energy future. The Mott-Schottky interinterface catalyst with atomically dispersed Ru nanoparticles was constructed by oxidation-amolysis modified lignin (Ru@OALC) to achieve high efficiency hydrogen evolution (TOF 10.45s ⁻¹). The AEMWE device was driven to operate stably at 1.69V ultra-low voltage for 800 hours (0.5A cm⁻²). The dynamic catalytic mechanism of HER driven by interfacial electric field was revealed by in-situ spectroscopy and DFT theory.