Synthesis of Bifunctional Catalyst for Aqueous Phase Reforming of Biomass

This study reports the synthesis of novel bifunctional catalytic material and its utilization in catalytic aqueous phase reforming of biomass to enhance selectivity and conversion into hydrogen and higher hydrocarbons. The synthesis involved the preparation of mesoporous aluminosilicate catalyst by using the surfactant assisted sol-gel method followed by immobilization of Ni/Cu/Ru. The alkoxides precursors for aluminoslicate were chosen in a desired weight ratio and mixed with the Pluronic 123 surfactant. After hydrolysis and condensation steps, the gel obtained was aged for 24 h, treated in ethanol at 60^oC for 2 hrs and finally calcined at 400-600^oC at a heating rate of 1^oC/min. The mesoporous structure was analyzed using TEM and the phase composition was determined using powder X-ray diffraction. The mesoporous aluminosilicate material was contacted with ethanol/water solution of Ni and Cu salts for 8 h at 40-50^oC. The powder obtained was dried at 105^oC for 2 h and reduced under H₂ environment for 2 h and further characterized by SEM/EDX to determine the loading of metal ions on the mesoporous aluminosilicate material. As received biomass (pine wood and cellulose) were subjected to aqueous phase liquefaction process at 250^oC in a high pressure reactor in presence of homogeneous Ni or Cu salts as catalyst and H₂ generation was monitored. The slurry obtained after liquefaction process was processed further to recover the residue and bio-oil. The Ni/Cu loaded meosporous catalyst was contacted with the processed slurry obtained after liquefaction and the H₂ and higher hydrocarbon formation was investigated. The results obtained on H₂ generation during catalytic liquid phase liquefaction processing of a biomass, SEM/EDX analysis of Ni/Cu loaded aluminosilicate, and selective conversion into higher hydrocarbons will be presented. In addition the mechanistic model based on catalytic free-radical chemistry will also be presented, and results discussed.