Efficient Alkylation of Benzyloxybenzene to High‐carbon Phenolic Compounds by Modulation of Brønsted Acid Strength of SPDVB‐t Catalysts

Sulfonic acid group functionalized materials with Brønsted acid sites play a key role in the catalytic conversion of oxygen‐containing compounds with α‐O‐4 bonds to high‐carbon phenolic compounds. However, it is challenging to generate high‐carbon phenolic compounds with high selectivity due to the limited number of sulfonic acid groups grafted on the carrier and the difficulty in regulating the acid strength. Herein, this study utilizes concentrated sulfuric acid to sulfonate poly‐divinylbenzene to obtain sulfonated polymer nanotube catalysts with Brønsted acid sites. Their acid strength was regulated simply by controlling the sulfonation time. The π‐π conjugation effect between the benzene rings in the polymer backbone and the sulfonic acid groups alters the electron cloud density of the C‐S bond, leading to the dissociation of H+ from sulfonic acid groups. This mechanism facilitates the highly selective alkylation of benzyloxybenzene, yielding bicyclic phenolic compounds, specifically 2‐benzylphenol and 4‐benzylphenol. The optimal material (SPDVB‐14) completely converts benzyloxybenzene into phenolic compounds under mild conditions (140 °C, 0.2 MPa N2, 1.5 h), achieving a yield of up to 87.5% for both 2‐benzylphenol and 4‐benzylphenol. These high‐carbon phenolic compounds have potential application value in diesel/jet fuel and liquid organic hydrogen carriers.