Promotional effect of indium on CuO–CeO2 catalysts for low-temperature CO oxidation

Abstract

Copper-based catalysts have been extensively used in the oxidation of CO due to their low cost and high efficiency, especially copper–cerium catalysts. In this work, CuO/CeInO_x catalysts were prepared by a deposition–precipitation method, with the physical/chemical properties and CO oxidation activity systematically investigated. The In dopant is incorporated into the CeO₂ lattice in the near-surface region. In–O–Ce species promote the generation of surface oxygen vacancies and increase the number of Cu¹⁺ sites. As a result, the Cu/Ce₉₀In₁₀O_x catalyst exhibits a superior CO oxidation activity at low temperatures (T₉₀ = 84 °C (without 3 vol% H₂O) and T₉₀ = 110 °C (with 3 vol% H₂O)). The TOF of Cu/Ce₉₀In₁₀O_x at 90 °C is 1.19 times (without 3 vol% H₂O) and 3.13 times (with 3 vol% H₂O) that of Cu/Ce₁₀₀In₀O_x.