Preparation of nano-NiO particles and evaluation of their catalytic activity in pyrolyzing cellulose

Nano-NiO particles were prepared by using the homogeneous precipitation method, and characterized by using different approaches such as (X-ray Diffraction) XRD, BET, and transmission electronic microscope (TEM). The prepared nano-NiO particles were found to be spherical in shape, could be well dispersed, and demonstrated weak agglomeration. They generally had high purity and a fine crystal phase of cubic syngony with a mean size of ∼7.5 nm and specific surface area of 187.98 m2/g. Meanwhile, evaluation of the catalytic activity of developed nano-NiO particles in pyrolyzing cellulose was carried out in comparison with that of micro-NiO, in the same conditions, using TGA. The results indicated that the activation energy in the presence of micro-NiO and nano-NiO reduced by 12.24 and 22.42 kJ/mol, respectively, in comparison with that of pure cellulose pyrolysis. This resulted in the initial temperatures of cellulose decomposition being 10°C and 19°C lower than that of pure cellulose, and the final char yield was further decreased. Compared to the micro-NiO, nano-NiO particles demonstrated an even superior activity.