The combination of copper and cobalt in the mixed metal oxides phase attracted considerable interest owing to their distinct characteristics and wide-ranging applications across various domains. In this study, we adopt a facile co-precipitation approach to prepare the hollow carbon spheres (HCSs) embedded with CuCo2O4 nanoparticles to enhance the catalytic activity. HCSs are prepared using a hydrothermal template method followed by the removal of the silica template. The resulting CuCo2O4 and HCSs are characterized by using X-ray diffraction, Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, and Thermo-Gravimetric Analysis to ensure structural integrity and composition. Then, the CuCo2O4 nanoparticle is doped on the porous structure of HCSs using a surface loading method and used as a catalyst for the transfer hydrogenation of acetophenone. The scope is extended using various substrates without a hydrogen source. This nano-catalytic system shows better yields in mild reaction conditions. There was no leaching of the material into the reaction system even after five cycles, thus confirmed by ICP-MS.

Copper cobaltate loaded on hollow carbon spheres: enhanced catalytic performance for transfer hydrogenation of acetophenone derivatives
    Abstract
        Graphical abstract
    1 Introduction
    2 Materials and methods
        2.1 Materials
        2.2 Preparation of the HCSs
        2.3 Preparation of CuCo2O4
        2.4 Loading of different wt% of CuCo2O4 on HCSs
        2.5 Organic transformation
    3 Results and discussion
        3.1 XRD analysis
        3.2 FT-IR analysis
        3.3 SEM and FE-SEM analyses
        3.4 TGA analysis
        3.5 BET analysis
        3.6 XPS analysis
        3.7 Zeta potential
    4 Catalytic application
        4.1 Optimization
        4.2 Substrate scope
        4.3 Plausible mechanisms
        4.4 Reusability
    5 Conclusion
    Acknowledgements 
    References

• Boopathi Shagunthala Hariprasad(Nano‑Catalysis Research Lab, Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore 632014, Tamil Nadu, India)
• Jagadeesh Likhith(Nano‑Catalysis Research Lab, Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore 632014, Tamil Nadu, India)
• Senthilkumar Aravind(Nano‑Catalysis Research Lab, Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore 632014, Tamil Nadu, India)
• Sreenidhi M Varma(Nano‑Catalysis Research Lab, Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore 632014, Tamil Nadu, India)
• Sundaram Ganesh Babu(Nano‑Catalysis Research Lab, Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore 632014, Tamil Nadu, India) Corresponding author
• Kasirajan Prakash(Department of Chemistry, PSR Engineering College, Sivakasi 626140, Tamil Nadu, India)