Catalytic hydrogenation performance of 2,2,4,4-tetramethyl-1,3-cyclobutanedione with Ru/activated carbon catalyst

In this study, a highly dispersed Ru/AC catalyst was prepared via an isovolumetric impregnation-chemical reduction method for the selective hydrogenation of 2,2,4,4-tetramethyl-1,3-cyclobutanedione (TMCB) to 2,2,4,4-tetramethyl-1,3-cyclobutanediol (CBDO). The catalytic performance was evaluated in a high-pressure reactor with a high substrate concentration of 9 wt% under industrially relevant conditions. The influence of key process parameters on hydrogenation efficiency was systematically investigated, and the catalyst’s stability over multiple reaction cycles was thoroughly assessed. Comprehensive characterization using XRD, BET, and TEM confirmed the atomic-level dispersion of Ru nanoparticles on the activated carbon support, with an average particle size of 0.4 nm. XPS and SEM analyses conducted before and after the reaction revealed that catalyst deactivation primarily stemmed from oxidation, leaching, and agglomeration of metallic Ru⁰ species, resulting in a progressive loss of active sites. The Ru/AC catalyst, under optimized reaction conditions (4 wt% Ru loading, 130 °C, 4 MPa H₂ pressure, and 1 h reaction time), afforded a CBDO yield of 99%, retaining a high yield of 90% even after 10 consecutive catalytic cycles.