Selective hydrogenation of levulinic acid using mechanochemically prepared Cu/manganese oxide catalysts Nayan Jyoti Mazumdar, Praveen Kumar 2 , Miryam Arredondo-Arechavala, Haresh Manyar Queen's University Belfast, UK Mechanochemistry is one of the most intriguing techniques for catalyst preparation, having potential advantages over conventional methods, such as higher metal dispersion, smaller metal nanoparticle sizes, green solvent-less synthesis. Mechanochemical catalyst synthesis can be performed under solvent-less conditions which enhances the environment friendliness of the process. In this work, we have compared the structural properties of a range of copper (Cu) on manganese oxide octahedral molecular sieve (OMS-2) catalysts prepared by conventional wet impregnation as well as mechanochemical techniques. We have also evaluated the catalytic activity of our catalysts using liquid-phase hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) as an exemplar reaction. LA is a biomass derived platform chemical and GVL is a high-value product with wide range of applications as solvents and precursor for fuel additives. It is also possible to further upgrade GVL to jet fuels via ketonisation pathway. To corelate the catalyst structure and activity, we thoroughly characterised our materials using different techniques such as powder XRD, ICP-OES metal analysis, FTIR, HRTEM, H2-TPR, and N2 physisorption analyses.
Figure 1 As seen from Figure 1a and 1b, Cu crystallite sizes were measured to be in the range of 24-27 nm for catalyst prepared by wet impregnation method, and <2-3 nm for catalyst prepared by mechanochemical method. Catalysts prepared by mechanochemical method showed higher dispersion of Cu nanoparticles on the surface of OMS-2 nanorods. Catalytic activity of the catalysts prepared by ball-mill and wet-impregnation method clearly shows the effect of particle size of Cu upon the hydrogenation of LA. Catalysts prepared by solvent-free mechanochemical method having same loading of Cu in comparison to other methods have shown superior activity to LA conversion. This work is in correlation to sustainable synthesis that mechanochemistry reduces solvent waste and is an economically more viable process regarding environmental impact, energy usage and cost of operation. References 1. N. Mazumdar et al., R. Soc. Open Sci., (2022). http://doi.org/10.1098/rsos.220078 2. J. Keogh et al., Fuel, 310, (2022) 122484. 3. K. Ralphs et al., ACS Sustain. Chem. Eng., 10, (2022) 6934-6941.
P67
© The Author(s), 2022
Made with FlippingBook Learn more on our blog