Low-temperature Water-gas Shift Reaction Enhanced by Oxygen Vacancies in Pt-loaded Porous Single-crystalline Oxide Monoliths.

Water-gas shift (WGS) reaction at low temperature plays an important role in hydrogen production from fossil fuels and hydrogen purification for proton-exchange membrane fuel cells. However, the activation of H 2 O is a critical reaction step that greatly limits the overall performance during WGS reaction. Here we fabricate porous single-crystalline (PSC) MoO 3 monoliths at 1 cm scale and deposit atomic-layered Pt clusters at the lattice surface to create the interfacial system toward the low-temperature WGS reaction. The single-crystalline nature stabilizes the oxygen vacancies (V O ) at lattice and facilitates the effective activation of H 2 O at the interface. We show the highest Pt-normalized activity of 0.86 mol CO  mol Pt -1  s -1 for the ultra-low temperature WGS reaction at 120 °C. The single-crystalline features with enhanced fluxion in porous architectures lead to outstanding performance without visible degradation even after continuous operation for 100 hours.