Development and Application of Noble Metal Based Catalysts for Bio-oil Upgrading Process

摘要

Sustainable energy has emerged as one of the most critical challenges to sustainable global development in the 21st century. As the reserves of fossil fuels are diminishing, there is an urgent need for alternative liquid fuels – from renewable resources - to meet increasing energy demand. Biomass-derived bio-oil is a potential resource to solve this issue, as a drop-in petroleum replacement. However, bio-oil has several technical barriers such as high oxygen and water content, poor stability, low heating value and corrosivity. Therefore, further effort is required to upgrade bio-oil to an advanced fuel parallel to petroleum. This thesis focuses upon the preparation of novel nanomaterials, and their potential application in bio-oil hydrogenation reactions.Chapter 1 elaborates the background information of energy resources, bio-oil production, bio-oil upgrading methods, hydrodeoxygenation (HDO) process, synthesis of noble metal nanoparticles (NPs) and novel catalytic system using induction heating. Chapter 2 systematically describes the synthesis of porous platinum (Pt) nanostructures with size ranging from 10 to 150 nm by a facile seed-mediated method with formation mechanisms fully discussed, as well as their high catalytic activity towards aqueous-phase hydrogenation of the bio-oil model compound, acetophenone. In Chapter 3, monodispersed cubic Pd NPs with a size range of 5 to 19 nm and ~18nm concave cubic Pd NPs were prepared through a one-pot hydrothermal method and a seed-mediated method. These Pd NPs were applied in the hydrogenation of benzaldehyde to investigate the effect of size, shape, and temperature on catalysis. Chapter 4 reports the preparation of four different phased iron oxide NRs (β-FeOOH, α-Fe2O3, Fe3O4@C, and γ-Fe2O3), and their use as recoverable support materials for Pd nanocubes. The investigation of support effect on hydrogenation reactions showed that Fe3O4@C/Pd catalyst has best catalytic activity due to 2-3 times larger surface area and better Pd dispersity. In Chapter 5, a novel catalytic system was developed using Fe3O4@C/Pd as both a catalyst and a nano-heater that raises the reaction temperature via magnetic induction heating. The conversion efficiency of sodium ferulate to 3-(3-hydroxy-4-methoxyphenyl) propanoate was found to significantly increase by 32% at 80C when the heat was delivered via magnetic induction heating as opposed to the traditional oil bath heating method, presumably due to the effectiveness of ‘nano-heating’ and ‘nano-stirring’. Finally, conclusions and the future work are detailed in Chapter 6.