Glycerol steam reforming for hydrogen production over bimetallic MNi/CNTs (M=Co, Cu and Fe) catalysts

The bimetallic MNi/CNTs (M=Co, Cu and Fe) catalysts with controlled metal distribution were prepared by a two-step impregnation method. The catalysts were characterized by N-2 adsorption/desorption, XRD, XPS, TPR, HAADF-STEM, TEM and TG to study the porous structure, changes in crystalline phases during the reaction, surface chemical state, reducibility, the element distribution, sintering of metal particles and the deposited coke for the calcined and/or spent catalysts. The results showed that the Ni oxide was successfully introduced into the cave and the other one was dispersed on the external wall of CNTs. The addition of the secondary metals had significant influences on the reducibility, resulting in the quite different surface properties which was directly linked to the products distribution in glycerol reforming reaction. The sample CoNi/CNTs performed better in both anti-sintering and coke resistance, and over which the product was more selective to hydrogen by enhancing the water gas shift reaction.