Synthesis of precious metal nanoparticles supported on bacterial biomass for catalytic applications in chemical transformations

[摘要] Bacteria are used to ‘grow’ and scaffold precious metal nanoparticles possessing certain catalytic activities. Focusing on Escherichia coli, this thesis aims to investigate the catalytic behaviours of E. coli-supported palladium (bio-Pd/E. coli) or bimetallic gold-palladium (bio- AuPd/E. coli) in hydrogenations and oxidations operated in laboratory-scale three-phase slurry reactors. A discussion of hydrodynamics, mass transfer, reaction mechanisms and corresponding reaction performance is systematically presented for two major industrially important reactions: soybean oil hydrogenation and benzyl alcohol oxidation. Thermogravimetric analysis indicated a suitable operating temperature of below 175\(^0\)C for the E. coli-supported catalyst. A loading of 5 wt%Pd on E. coli showed an average particle size of 4.31 nm estimated by TEM measurements and a crystallite size of 4.12 nm using Scherrer’s equation from obtained X-ray powder diffraction data. This was smaller than an active particle diameter of 12.77 nm for 5wt%Pd/Al\(_2\)O\(_3\) (determined by CO chemisorption). It is concluded that biomass-supported precious metal catalyst is an environmentally attractive alternative to conventional heterogeneous catalyst for application in industrial catalytic processes.

[发布机构] University:University of Birmingham;Department:School of Chemical Engineering

[关键词] T Technology;TP Chemical technology