Iridium Catalyst Immobilized on Crosslinked Polyethyleneimine for Continuous Hydrogen Production Using Formic Acid

Abstract Hydrogen is an alternative fuel that can play a critical role in achieving net zero emissions, leading to global environment sustainability. An iridium‐immobilized catalyst based on polyethyleneimine (PEI) was synthesized and utilized for hydrogen production via formic acid dehydrogenation (FADH). Iridium complex is cross‐linked with its ligand and PEI to form the immobilized catalyst, where the iridium content could be easily varied in the range of 1–10 %. The structure of the iridium‐immobilized catalyst was confirmed using solid‐state NMR, DNP NMR, and FTIR spectroscopies. The iridium‐immobilized catalyst with PEI showed excellent catalytic activity for FADH, exhibiting the catalyst's highest turnover frequency (TOF) value of 73 200 h −1 and a large turnover number (TON) value of over 1 130 000. The catalyst could be used for continuous hydrogen production via FADH, exhibiting high durability for over 2 000 h with TON value of 332 889 without any degradation in catalytic activity. The obtained hydrogen gas was evaluated for power generation using a standard fuel cell, as well as achieved 5 h of stable power generation.