Boosted catalytic activity by metal-oxide interface in porous single-crystalline niobium oxide monoliths

Introducing and stabilizing oxygen vacancies in the lattice of oxide support materials has been a huge challenge to boost the catalytic activity in redox reaction. Herein, we fabricate porous single-crystalline Nb2O5 monoliths at the centimeter scale, then we introduce the oxygen vacancies in lattice by reduction treatment and stabilize the oxygen vacancy defects by the ordered lattice. We then deposit Pt clusters at surface in the porous microstructures to construct an interfacial system and we show the significantly enhanced surface oxygen exchange coefficient. As a case study, we demonstrate the complete CO oxidation with air at 110 °C and 30,000 mL g-1 h-1 conditions, following the Mars-van Krevelen mechanism, with no visible performance attenuation after a continuous operation of ~500 h. At 60,000 mL g-1 h-1 and 110 °C, the CO conversion rate decreases to 83.8% and ultimately remains 76.3% after 185 h of long-term operation. Introducing and stabilizing oxygen vacancies within oxide supports remains a significant challenge for enhancing catalytic activity in redox reactions. Here, the authors fabricate centimeter-scale porous single-crystalline Nb₂O₅ monoliths and deposit Pt clusters on their surfaces, creating an interfacial system that markedly improves catalytic CO oxidation.