Hydrogen Production By Aqueous-phase Reforming Of Biomass Depolymerization On Ni/Zn/Al Catalysts Derived Hydrotalcite

Humans make more focus on renewable and clean energy due to the depletion and pollution of the fossil energy,thus,hydrogen becomes the first choice with higher calorific value and nonpolluting,However,about 95 % of the hydrogen comes from fossil fuel.So the abundant biomass and its derivative turn into a very important material for hydrogen production instead of fossil fuel.The methods of steam reforming or ionization for hydrogen production consume high energy so that the application of them is limited,moreover,the process of steam reforming happens in multistage reactor for generating hydrogen.Compared to steam reforming,hydrogen production on aqueous-phase reforming（APR）referred by Dumesic reacts simply and can realize producing hydrogen in one step.The catalysts need ability of breaking C-C bonds and promoting water-gas shifts reaction in the aqueous-phase reforming reaction.Most of active components in the catalysts belong to the Ⅷ groups transition metals.In this study,the catalysts are prepared by coprecipitation to form hydrotalcite.This text investigates the catalytic performance on the reaction of aqueous-phase reforming of ethylene glycol for hydrogen production,at the same time,the reaction conditions are optimized.Some major results are obtained as follows: The Ni/Zn/Al catalyst derived hydrotalcite exhibits the best performance on the APR of ethylene glycol in the five catalysts（Ni/Zn/Al,Ni/Cu/Al,Ni/Mg/Al,Ni/Sn/Al and Ni/Mn/Al）.The best molar ratio of Ni/Zn/Al is 2:2:1 with 100 % H₂ selectivity and 99.27 % conversion in the APR.The calcination temperature of 500 oC contributes to good catalytic effect for the Ni₂Zn₂Al catalyst derived hydrotalcite.The ZnO in the catalysts is supposed to promote hydrogen production.The test make deep analysis on the catalysts derived hydrotalcite through XRD,H2-TPR,SEM and BET.Trough optimizing the reaction conditions,the best reaction conditions are got,which are reaction temperature of 225 oC,reaction pressure of 2.6 MPa and reaction time of 3 h with 0.2 g of Ni₂Zn₂Al catalyst derived hydrotalcite.