Affiliation:
1. Catalysis and Inorganic Chemistry Division CSIR-National Chemical Laboratory Dr. Homi Bhabha Road Pune 411 008 India
2. Academy of Scientific and Innovative Research (AcSIR) Ghaziabad 201 002 India
3. Materials Science and Catalysis Division Poorna Prajna Institute of Scientific Research (PPISR) Bidalur, Devanahalli Bengaluru 562164 India
4. Lalit Narayan Mithila University Darbhanga Bihar India
Abstract
AbstractThis work describes the comparison of the catalytic performances of α‐MnO2 nanorods synthesized by a facile hydrothermal approach at varying temperatures (140–200 °C). The structure and morphology of these nanorods were analyzed by XRD, N2‐physisorption, NH3‐TPD, Raman, SEM, HRTEM, and XPS. The prepared α‐MnO2 nanorods also performed exceptionally well in the catalytic oxidation of cyclohexanone to dicarboxylic acids under mild reaction conditions. The characterization results conferred that there is a significant influence of hydrothermal temperatures on the textural properties, morphology, and catalytic activity. Notably, the α‐MnO2 nanorods obtained from 180 °C hydrothermal conditions outperformed other catalysts with 77.3 % cyclohexanone conversion and 99 % selectivity towards acid products such as adipic acid (AA), glutaric acid (GA) and succinic acid (SA). The improved catalytic activity may be attributed to the interaction of the bifunctional Mn3+/4+ redox metal centres and surface acidic sites. The present oxidation reaction was found to be a promising eco‐benign process with high selectivity for the production of commercially significant carboxylic acids from cyclohexanone.