Reduction kinetics of nickel oxide dispersed on MCM-41

Abstract

Nickel oxide was supported on MCM-41 using the precipitation method. Reduction kinetics of supported and unsupported nickel oxide was studied using non-isothermal methods to investigate the change in activation energy and the reduction reaction mechanism. Activation energy was determined using the Kissinger’s method and Straink’s method. Model discrimination was done using the Hancock-Sharp analysis and Malek’s method. The support influenced the reduction kinetics by increasing the activation energy. The reaction mechanism shifted from Avrami-Erofeev model in the unsupported to three-dimensional diffusion-controlled model in the supported nickel oxide. The higher activation energy and the model discrimination in the case of nickel oxide supported on MCM-41 indicates the diffusion of vacancies is the rate limiting step. The reduction mechanism of nickel oxide supported on MCM-41 was proposed in agreement with literature and current study.