Engineering of Metal–Support Interfaces and Cu _n -O _v Synergistic Sites in Cu/CeO ₂ Catalyst for Enhanced Low-Temperature CO ₂ Hydrogenation

Designing supported metal catalysts with strategically engineered metal–support interfaces (MSI) remains pivotal yet challenging in heterogeneous catalysis. Herein, we present a Cu@CeNF catalyst comprising Cu nanoparticles (Cu NPs) anchored on hollow CeO2 fibers with abundant oxygen vacancies (Ov) and strong metal–support interaction (SMSI), synthesized via a one-pot electrospinning approach. This architecture generates a high density of synergistic Cu-oxygen vacancy (Cun-Ov) interfacial sites, significantly enhancing the catalytic performance in the reverse water–gas shift (RWGS) reaction. Compared to its counterpart Cu/Ce-CP, prepared by the coprecipitation method and showing a CO2 conversion of only 4.5%, CuCe@NF delivers a substantially higher CO2 conversion of 28.9% with 99.9% CO selectivity at 350 °C. Moreover, it maintains long-term stability over 228 h at 300 °C under a high GHSV of 60,000 mL·g–1·h–1. Comprehensive insitu spectroscopic characterizations combined with DFT calculations reveal that the synergetic effects of SMSI and the dense Cun-Ov interfaces in CuCe@NF modulate the d-band center of Cu closer to the Fermi level. This modulation facilitates interfacial charge transfer, which promotes CO2 activation, enhances formate intermediates formation, and accelerates CO desorption. This work demonstrates that engineered metal–oxygen vacancy interfaces can effectively tailor electronic structures to enhance CO2 activation, offering a broadly applicable design strategy for developing highly active catalysts in low-carbon energy conversion.