Atomically dispersed Ru and Ru nanoparticle interplay the selective hydrogenation for efficient C–O bond cleavage of lignin

A 100% lignin β -O-4 model conversion with 93.1% monomer selectivity and a high TON was obtained. • The interplay between Ru particle and single atom contributed to the high performance. • Favorable stability under high-temperature heating and high-pressure with reusability > 97%. Catalytic hydrogenolysis is a promising strategy for converting lignin into valuable aryl platform chemicals, contingent upon the availability of high-performance catalysts. The philosophy for the catalyst rational design towards high conversion and selectivity was rarely reported to the best of our knowledge. We illustrate the synergistic interplay between Ru particles and single atoms, contributing to the high catalytic performance. The N-doped carbon-supported Ru catalyst is designed by combining collagen fiber-immobilized tannin adsorption with carbonization (TNC). The Ru is finely dispersed on the TNC support in the form of both single atoms and nanoparticles at a low metal loading of 0.91 wt% (noted as Ru/TNC). It achieved a 100% conversion with a 93.1% aromatic monomer yield in the catalytic hydrogenolysis of lignin β –O–4 model 2-phenoxy-1-phenylethanol (PPE) at 260 °C and 2 MPa H 2 . The primary products of this reaction included ethylbenzene, cyclohexanol, and ethylcyclohexane, and a high turnover number (TON) of 955 was obtained, which surpassed most reports. Specifically, the Ru particle sites facilitate efficient H 2 dissociation, while the single-atom sites provide a weakly adsorbing environment for reaction intermediates due to electron-rich isolated Ru atoms, thereby effectively suppressing over-hydrogenation. This work offers a promising catalyst rational design principle for selective hydrogenation for efficient C–O bond cleavage of lignin, demonstrating significant potential in transforming lignin into value-added platform chemicals. Download: Download high-res image (151KB) Download: Download full-size image Possible reaction pathway on Ru/TNC catalyst consisting of Ru particle and Ru single atom. The intermediates easily desorbed over Ru single atom site due to the weak adsorption. Purple ball: Ru atom, red ball: N atom, white ball: H atom where Ru particles serve as H* species supply pump due to H spillover.