Controllable synthesis of metallo-alkoxide precursor-derived nickel aluminate spinels using TEA-gel process and morphology-dependent reducibility

A study was made of the different preparation methods affecting the morphology and reducibility of the obtained NiAl2O4 spinels. The NiAl2O4 with various morphologies has been fabricated through the dependent-control of TEA (triethanolamine)-gel parameters. Compared to the NiAl2O4 prepared from a direct calcination of spinel precursors, the superb structural characteristics of the NiAl2O4 including large surface area and well-defined interconnected nanoparticles were observed via the TEA-gel route. The NiAl2O4 prepared by TEA-gel method yields the highest degree of surface reduction with the largest amount of metallic nickel phase found in the spinels. This spinel also had the lowest initial temperature of reduction. The results indicate that the NiAl2O4 prepared by the TEA gel technique using our new spinel alkoxide precursor has a promising prospect in the preparation of nickel catalyst supports where there is a need to avoid the traditional multiple procedures that are time-, solvent-as well as high energy-consuming. (C) 2016 Published by Elsevier B.V.