Tailoring high-performance aluminosilicates plays a key role in the efficient and clean production of high value chemicals. Recent works reveal that pentacoordinated Al (Al V) species can significantly enhance the Brønsted acidity of amorphous silica-alumina (ASA), compared to those typically dominated by tetracoordinated Al species. However, the controlled synthesis of Al V-rich ASAs is challenging. Employing xylene as the solvent in the flame-spray pyrolysis process we synthesized Al V-rich ASAs successfully. The high combustion enthalpy of xylene (36.9 kJ/ml) results in high flame temperature, promoting the formation and distribution of metastable Al V species in the silica network forming Brønsted acid sites. This provides a promising way for the controlled synthesis of Al V-rich ASAs with higher Brønsted acidity. As an example, the Al V-rich ASAs are shown to exhibit superior catalytic performance in the phenylglyoxal conversion to ethyl mandelate in ethanol compared to that achieved with other acid catalysts, providing an ethyl mandelate yield of 99.8 %.

This is a repository copy of Enhancing hydrogen production from the pyrolysis-gasification of biomass by size-confined Ni catalysts on acidic MCM-41 supports.

This is a repository copy of Effect of calcium addition on Mg-AlOx supported Ni catalysts for hydrogen production from pyrolysis-gasification of biomass.

Abstract:Thermo-chemical processing of biomass is a promising alternative to produce renewable hydrogen as a clean fuel or renewable syngas for a sustainable chemical industry. However, the fast deactivation of catalysts due to coke formation and sintering limits the application of catalytic thermo-chemical processing in the emerging bio-refining industry. In this research, Fe-Zn/Al 2 O 3 nanocatalysts have been prepared for the production of hydrogen through pyrolysis catalytic reforming of wood sawdust. Through characterization, it was found that Fe and Zn were well distributed on the surface with a narrow particle size. During the reactions, the yield of hydrogen increased with the increase of Zn content, as Zn is an efficient metal promoter for enhancing the performance of the Fe active site in the reaction. The 20% Fe/Al 2 O 3 catalyst with Zn/Al ratio of 1:1 showed the best performance in the process in relation to the hydrogen production and resistance to coke formation on the surface of the reacted catalyst. All the catalysts showed ultra-high stability during the process and nearly no sintering were observed on the used catalysts. Therefore, the nanocatalysts prepared in this work from natural-abundant and low-cost metals have promising catalytic properties (high metal dispersion and stability) to produce H 2 -rich syngas with optimal H 2 /CO ratio from the thermo-chemical processing of biomass.

No abstract