Heterostructured Ni/NiO Nanocatalysts for Ozone Decomposition

Water vapor is one of the main factors that deactivate ozone decomposition catalyst, which limits its application in practical conditions. In this work, heterostructured Ni/NiO nanocatalyst is synthesized using citric sol-gel method, which displays 100% removal efficiency to 1000 ppm ozone at room temperature in dry flow (space velocity 240,000 mL g-1h-1). Importantly, the removal efficiency is still above 98% at high relative humidity RH 90% after 8 h test, which is twice the efficiency of the pure NiO nanoparticles. The high humidity resistance of Ni/NiO nanocatalyst can be interpreted as the weak adsorption of water on its surface, as proved by the H2O temperature programmed desorption, X-ray photoelectron spectroscopy, and chemiluminescence (CL). Surface atomic models are also established to present reaction path of ozone on catalyst surface under high humidity. In addition, as a proof-of-concept, heterostructured Ni/NiO foam monolithic catalyst has been synthesized with nearly 100% decomposition effi...