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 CeO 2 fibers with abundant oxygen vacancies (O v ) and strong metal–support interaction (SMSI), synthesized via a one-pot electrospinning approach. This architecture generates a high density of synergistic Cu-oxygen vacancy (Cu n -O v ) 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 CO 2 conversion of only 4.5%, CuCe@NF delivers a substantially higher CO 2 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 Cu n -O v interfaces in CuCe@NF modulate the d-band center of Cu closer to the Fermi level. This modulation facilitates interfacial charge transfer, which promotes CO 2 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 CO 2 activation, offering a broadly applicable design strategy for developing highly active catalysts in low-carbon energy conversion.