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Lignin is a by‐product of biorefineries and pulp and paper manufacturers. Lignin is a renewable source of phenolic precursors for fuels and chemicals. Hydrogenolysis of lignin cleaves the abundant β‐O‐4 bonds and releases phenolics. However, selective hydrogenolysis of lignin's β‐O‐4 bonds is challenging because it requires high‐pressure H2. Here we show efficient hydrogenolysis of lignin model compounds and technical lignin by Ru/C catalyst and internal hydrogen. The aliphatic hydroxyl groups (Cα−OH) in lignin enabled Ru‐catalyzed dehydrogenation of internal hydrogen and the formation of reactive keto intermediate, which facilitated the β‐O‐4 cleavage into phenolic monomers. Furthermore, solvents that had a high donor number (Lewis basicity) enhanced the yield of phenolic monomers, equal to 27.9 wt.% from technical lignin. These findings offer a novel approach for biorefineries to design lignin isolation processes and/or solvent systems to maximize phenolic monomers and to control product selectivity/stability. [ABSTRACT FROM AUTHOR]

Catalytic pathways to produce high carbon number compounds from benzyl phenyl ether require multiple steps to break the aryl etheric carbon–oxygen bonds; these steps are followed by energy-intensive processes to remove oxygen atoms and/or carbon–carbon coupling. Here, we show an upgrading strategy to transform benzyl phenyl ether into large phenolic (C12–C22) compounds by a one-step C–O breaking and C–C coupling catalyzed by metal triflates under a mild condition (100 °C and 1 bar). Hafnium triflate was the most selective for the desired products. In addition, we measured the effect of solvent polarity on the catalytic performance. Solvents with a polarity index of less than 3.4 promoted the catalytic activity and selectivity to C12–C22 phenolic products. These C12–C22 phenolic compounds have potential applications for phenol–formaldehyde polymers, diesel/jet fuels, and liquid organic hydrogen carriers. [ABSTRACT FROM AUTHOR]

[Display omitted] • We study phenol adsorption and tautomerization on cation-exchanged Lewis acidic BEA. • Charge transfer is a key factor in phenol adsorption on cation-exchanged Sn-BEA. • Catalytic activity of Sn-BEA for phenol tautomerization is improved by exchanging cations. • Catalytic activity of tetravalent metal centers is in the order Zr ~ Hf > Sn > Ti. • Results relate to developing catalysts for biomass-derived chemicals conversion. The effect of cation exchange and tetravalent metal substitution in Lewis acidic BEA zeolites for phenol adsorption and tautomerization was investigated by deriving the relevant reaction profiles with density functional theory calculations. The strongest adsorption interaction is when phenol chemisorbed to Li-Sn-BEA, due to the highest charge transfers from phenol to zeolites. Based on overall activation energies, the catalytic activity for phenol tautomerization on Sn-BEA can be improved with the exchange of cations. The catalytic activity of tetravalent metal centers substituted into BEA is compared and found in the order of Zr ~ Hf > Sn > Ti. [ABSTRACT FROM AUTHOR]