Catalysis Today, Vol.216, 205-210, 2013
Development of novel monolithic catalyst with porous hollow silica nanoparticles for selective hydrogenation reactions
Novel monolithic catalysts were prepared with Pd nano-catalysts on porous hollow silica nanoparticles (PHSNs, the supporting active sites) as washcoat and monolithic cordierite (MC) as the monolithic ceramic substrate. The coating of PHSNs could increase the surface area of MC for more than 10 times and also endue the coated layer with engineered porous hollow structure; therefore, the new monolithic catalysts were expected to keep both the excellent catalytic performance from the nano-washcoat and the fine mechanical properties from the monolithic substrate. The obtained samples were characterized with Scanning Electronic Microscope (SEM), ultrasonic vibration test and X-Ray Diffraction (XRD). SEM images showed that the monolithic catalysts were covered with a PdO/PHSNs washcoat of similar to 10 mu m thickness. Ultrasonic vibration tests indicated that the washcoat was anchored on monolithic substrates firmly. And XRD results demonstrated that the coating layers maintained the mesoporous hollow structure of PHSNs after being coated on MC. Finally, the catalytic properties of the novel Pd-loaded monolithic catalysts were determined by selective hydrogenation of acetylene in excessive ethylene, which showed that the selectivity of Pd-loaded PHSNs-Al2O3/MC catalysts was higher than other Pd supported catalysts, and adding a proper amount of Ag to PdO/PHSNs-Al2O3/MC catalysts could further enhance the catalytic performance. (c) 2013 Elsevier B.V. All rights reserved.