Enhancing the Catalytic Performance of NiO during the Transesterification of Waste Cooking Oil Using a Diatomite Carrier and an Integrated Ni Metal: Response Surface Studies.

Two types of NiO-based composites (NiO@diatomite and Ni/NiO@diatomite) were synthesized as modified products of enhanced catalytic performances during the transesterification reactions of waste cooking oil. The influence of the diatomite substrate and the integration of metallic Ni in inducing the catalytic activity were evaluated in a series of transesterification reactions. The experimental conditions were adjusted according to the response surface methodology and the central composite statistical design.