3D-mesoporous KIT-6 supported highly dispersed Pd nanocatalyst for dodecahydro-N-ethylcarbazole dehydrogenation

3D-mesoporous KIT-6 supported highly dispersed Pd nanocatalysts (Pd/KIT-6) are prepared via inorganometallic chemical adsorption (ICA) and sonochemical reduction for dodecahydro-N-ethylcarbazole (H12-NEC) dehydrogenation. First, Si-O--Na+ is obtained through the reaction between NaOH and silanol groups (Si-OH) on the surface of KIT-6. Then, Pd(NH3)(4)(2+) is adsorbed by Si-O--Na+ to obtain (Si-O-)(2)-Pd(NH3)(4)(2+) by ICA. Finally, PdEU/K6 is obtained through the reduction of (Si-O-)(2)-Pd(NH3)(4)(2+) using ultrasound-assisted isopropanol without adding any stabilizer. The Pd dispersion of Pd-EU/K6 is as high as 97%, which is mainly attributed to the ICA between Pd(NH3)(4)(2+) and Si-O--Na+. The Si-O-Pd on Pd-EU/K6 is formed through Pd coordination with O in Si-OH and acetone from isopropanol reduction, which stabilizes the Pd nanoparticles. Pd-EU/K6 shows excellent catalytic H12-NEC dehydrogenation performance with a dehydrogenation efficiency of 97.4% at 180 C for 6 h and a TOF of 7.08 min(-1) , which is attributed to its ultrahigh metal dispersion and favorable textural properties. The dehydrogenation efficiency of Pd-EU/K6 is maintained above 95% after 10 cycles.