Co-MnO/spontaneously polarized ceramic-carbon composite with oxygen vacancies for enhancing catalytic transfer hydrogenation of levulinic acid to γ-valerolactone

The utilization of organic molecules as in-situ hydrogen donors for producing γ-valerolactone (GVL) biofuel from biomass-derived levulinic acid (LA) represents one of the promising sustainable approaches. However, this process still faces challenges, including the difficult activation of the hydrogen source and the transport limitations of active hydrogen species. Herein, a Co-MnO/spontaneously polarized ceramic-carbon (Co-MnO/SPCE-C) composite catalyst, featuring a unique spontaneous polarization effect, was developed for catalytic transfer hydrogenation (CTH) of LA to GVL in the isopropanol/H 2 O (volume ratio = 1/19) cosolvent system. Co-MnO/SPCE-C contributed to an outstanding LA conversion of 99.9% and a favorable GVL yield of 93.5%, surpassing the performance achieved by comparative catalysts. Various characterization techniques demonstrate that SPCE with far-infrared emission and surface electric field increased the oxygen vacancies, thereby promoting hydrogen spillover and enhancing the properties of CoO x –MnO acidic sites. The 17 O NMR spectra reveal that SPCE activated water clusters by weakening the hydrogen bonding network. Moreover, D 2 O experiments show that SPCE facilitated the participation of water in the reaction. This work provides valuable insights into the development of an efficient strategy for producing GVL from LA. Before the catalyst can be considered for commercial applications, the focus in the future should be on a comprehensive computational analysis, long-term evaluation of catalyst stability, and additional industrial-scale testing.