Hydrogen-bonded network in interfacial water confer the catalysts with high formic acid decomposition performance

• Published in: Applied catalysis. B, Environmental Environmental, 2023-11, Vol.336, p.122913, Article 122913
• Main Authors: Gao, Nanxing, Han, Dongchen, Yang, Tongtong, Meng, Qinglei, Wang, Xian, Liu, Changpeng, Ge, Junjie, Xing, Wei
• Format: Article
• Language: English
• Subjects: Formic acid decomposition; Hydrogen-bonded network; Interfacial water
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2023.122913

The importance of the dynamic structural evolution of water in the solid–liquid interface cannot be overstated. However, the ubiquitous hydrogen-bonded network is notoriously difficult to probe owing to complex interfacial environment. Formic acid, a fair hydrogen-bond donor and acceptor, is a promising reversible hydrogen storage/release material. Herein, isotope-labeled in-situ mass spectrometry (MS) and operando surface-enhanced Fourier transform infrared measurements (operando FT-IR) reveal the central role of water during formic acid dehydrogenation. The water-promoted restructured HCOONa-Pd@ANI/C catalyst exhibits 100% selectivity, 100% conversion yield with high stability (even after 112 days) under ambient conditions. Coupled to a proton exchange membrane fuel cell, this integrated system reaches a high power density at 29.81 W⋅gPd−1. Our study demonstrates a new pathway involving water, the indispensable proton transfer and exchange through efficiently hydrogen-bonded network in light of operando experimental evidence. [Display omitted] •The reconstructed HCOONa-Pd@ANI/C catalyst demonstrates high efficiency and durability.•Operando experiments reveal the hydrogen shuttling and exchange.•A new reaction mechanism involving interfacial water is proposed.•On-site hydrogen production technology in tandem with PEMFCs is developed.