Synergistic Electronic Interaction in PdCu Alloy/TiO₂-NSs for Ambient Efficient Dehydrogenation of Formic Acid

Palladium-based catalysts are remarkable in endorsing hydrogen (H₂) generation through formic acid (HCOOH, FA) dehydrogenation under near-ambient conditions. Hydrogen energy efficiency depends on high-performance catalyst design. In this study, Pd-Cu nanoalloy catalysts with mutable atomic ratios are successfully fabricated on TiO₂ nanosheets (TiO₂-NSs).The synergistic electronic interactions between Palladium (Pd) and copper (Cu) are revealed through a density of states (DOS) analysis of alloy supported over a mixed valence state of Ti linked to oxygen vacancies (Vo) in TiO₂-NSs, Enhanced adsorption of target molecules reveals novel active sites for Formic acid dehydrogenation (FAD), with O─H bond cleavage via HCOO formate intermediate preceding C─H and C─O bond cleavage. Experimental and theoretical research demonstrates that the Pd-Cu/TiO₂-NSs (3:7) catalyst d electron redistribution and d-band center shift lower the activation energy for O─H bond cleavage, exhibit superior H₂ production than pure Pd and Cu, increasing Pd electron density due to synergistic effects from reactive crystal facets, defects, and strong metal support interactions (SMSI), lowering the activation energy for HCOOH dissociation step, generating carbon dioxide (CO₂) and H₂ with a unprecedented high turnover frequency (TOF) of 6268 mol_H2.h^-1.molPd^-1 at 303K with activation energy (E_a) of 15 KJ mol^-1. This attempt models an efficient HCOOH-to-hydrogen catalyst.