Morphology-dependent Ni@S-1 Catalysts Tailoring Hydrogenation and Hydrogenolysis of <i>m</i> -Cresol

Upgrading lignin-derived phenols to high-value arenes has garnered significant attention, while the major challenge lies in the selective cleavage of Caromatics–OH via hydroxyl hydrogenolysis. We systematically investigated the morphology-dependent properties of Ni@S-1 catalysts, encompassing their physicochemical characteristics, Ni nanoparticle properties, and the interaction between NiOx species and silicalite-1 (S-1) crystals as well as their performance in hydroxyl hydrogenolysis of vapor-phase m-cresol conversion. Both Ni@S-1 exhibited comparable Ni loading and crystal sizes but distinct morphologies, which originated from the complex intergrowth structures leading to variations in the dispersion and the location of Ni nanoparticles and significant differences in the shape-selective catalysis based on the confinement effect of S-1 channels for the vertical adsorption of m-cresol. Ellipsoidal Ni@S-1-Ell achieved m-cresol conversion of 96.9% (model reaction) along with hydrogenolysis products’ yield of 94.0%, which was 6.97 times in conversion and 22.38 times in yield of hydrogenolysis products than those of cylindrical Ni@S-1-Cyl under identical reaction conditions at 300 °C, 2.5 atm, and a feed rate of 6.0 g[m-cresol]/g[catalyst]·h.