Palladium nanoparticles on chitin-derived nitrogen-doped carbon materials for carbon dioxide hydrogenation into formic acid.

Utilizing waste carbon resources to produce chemicals and materials is beneficial to mitigate the fossil fuel consumption and the global warming. In this study, ocean-based chitin biomass and waste shrimp shell powders were employed as the feedstock to prepare Pd loaded nitrogen-doped carbon materials as the catalysts for carbon dioxide (CO 2 )/bicarbonate hydrogenation into formic acid, which simultaneously converts waste biomass into useful materials and CO 2 into a valuable chemical. Three different preparation methods were examined, and the two-stage calcination was the most efficient one to obtain N-doped carbon material with good physicochemical properties as the best Pd support. The highest formic acid yield was achieved of ∼77% at 100 °C in water with KHCO 3 substrate under optimal condition with a TON of 610. The nitrogen content and N functionalities of the as-synthesized carbon materials were crucial which could serve as anchor sites for the Pd precursor and assist the formation of well-dispersed and small-sized Pd NPs for boosted catalytic activity. The study puts forward a facile, inexpensive and environmentally benign way for simultaneous valorization of oceanic waste biomass and carbon dioxide into valuable products.