Pore Size Effects over Hierarchical Pore Hβ via Two-Stage Crystallization in Benzene Hydroalkylation

Hierarchical pore Hβ molecular sieve with high crystallinity were synthesized by two-step hydrothermal crystallization and seed-assisted, indicating that the method was more favorable to synthesize the hierarchical pore structure, and seed-assisted was helpful to improve the relative crystallinity and acid properties of Hβ. Compared with microporous Hβ, the hierarchical pore Hβ synthesized by a two-step hydrothermal crystallization strategy were presented high performance of benzene hydroalkylation. The conversion of benzene was 54.69 %, selectivity for cyclohexylbenzene was 74.31 %, and the catalyst activities was relatively stable within 280 h under hydrogen pressure of 2 MPa, temperature of 473 K, liquid space speed of 1 h⁻¹, and H₂/benzene molar ratio of 0.8 over Hβ loading 0.2 % (wt.%) Ru. Furthermore, the mesoporous structure of sample was beneficial to improve the diffusion rate of reactants and products and exposed more acidic active centers, which was conducive to the efficient hydroalkylation.