Harnessing MOF Derived Frustrated Lewis Pair-CeO₂ Nano Catalyst for CO₂-Activated Soft Oxidation of Furfural to...

CO₂ as a soft oxidant is scarcely explored in literature for furfural oxidation to furoic acid, and where CeO₂, capitalizes on the synergistic effect of FLPs for enhanced CO₂ reduction and furfural oxidation. This study presents a comparative analysis by the synthesis method to produce hydrothermal and MOF-derived CeO₂ nanocatalyst and their effect on the formation of oxygen vacancies and metastable Ce³⁺ ions. The normalized surface concentration derived from XPS At% and specific surface area effectively quantifies accessible Ce³⁺ sites and oxygen vacancies, capturing FLP sites. Oxygen vacancies near surface Ce³⁺ sites (FLPs) critically modulated the catalytic performance, and evidenced by high turnover number (TON). FTIR adsorption study revealed that CO₂ forms bidentate carbonate species and furfural, bi-coordination via η²- (C, O) mode on the catalyst surface. Further active site masking strategy helped to understand and validate the crucial role of FLPs. The Central Composite Design model was utilized to optimize the reaction conditions and obtained high furfural conversion (99%) and furoic acid selectivity (99%). The catalyst was resistant to active site leaching and exhibited excellent stability, recyclability, and robustness. The findings highlight a potential pathway for the catalytic soft oxidation of furfural to furoic acid by CO₂ utilization.