A comparative study on two types of nanocellulose products, namely CNCH2SO4 and CNCCr(NO3)3, derived from native MCC feedstock using concentrated H2SO4 and Cr(NO3)3 hydrolysis system, respectively, was conducted in this work. The optimal conditions for production of CNCCr(NO3)3 given by RSM methodology were 80 °C, 1.5 h, 0.8 M Cr(NO3)3 catalyst and solid–liquid ratio of 1:30. Under these experimental conditions, the manufactured CNCCr(NO3)3 displayed a spider-web-like fibrous morphology with a higher crystallinity of 86.5% ± 0.3%, yield of 83.6% ± 0.6%, and Tmax value of 344 °C. For comparison, the CNCH2SO4 hydrolyzed by H2SO4 exhibited a rice-shaped structure with the crystallinity index of 81.4% ± 0.1%, yield of 54.7% ± 0.3%, and Tmax value of 273 °C. Due to their crystallinity and aspect ratio differences, the isolated CNCCr(NO3)3 with higher crystallinity, higher aspect ratio (about 15.7) and more thermal stability could potentially be used as reinforcement material for application in various fields targeting specific properties. In conclusion, the proposed Cr(NO3)3 hydrolytic system is easy to implement and permits producing more thermally-stable nanocellulose with high yield under milder hydrolysis conditions, thus eluding the customary usage of conventional concentrated H2SO4 treatment for producing better quality nanocellulose.