Exploring the potential of copper-based catalysts for use IN CO OXIDATION reactions IN OXY-FUEL combustion engines
Álvaro Díaz-Verde, Enrique José Sanchís, Juan Carlos Martínez-Munuera, Avelina Garcı́a-Garcı́a, Pedro Piqueras
Abstract
• Copper ceria-zirconia catalysts surpass copper perovskite in oxyfuel conditions. • Copper (6 %) ceria-zirconia catalytically excels at high spatial velocities. • The CO 2 tolerance of copper (6 %) ceria-zirconia is lower than that of 1 % Pt/Al 2 O 3 . • Copper (6 %) ceria-zirconia surpass 1 % Pt/Al 2 O 3 at low supply of O 2 conditions. Copper/ceria-zirconia (Cu/Ce 0.8 Zr 0.2 O 2 ) and copper/perovskite (Cu/BaMnO 3 ) based catalysts have emerged as potential materials to be included in the formulation of oxidation catalysts for automotive applications, due to their tuneable redox properties, their high oxygen storage capacity and a favourable interaction between CuO and the corresponding supports. In this work, these formulations have been synthesised and tested as catalysts for CO oxidation reactions in different oxy-fuel combustion exhaust conditions. Their catalytic performances were compared with those obtained under conventional combustion conditions. The results showed that the copper/ceria-zirconia catalysts exhibited better catalytic performances than the perovskite-based ones in both exhaust conditions, which also promoted a high resistance to inhibition by the presence of CO 2 . Furthermore, Cu(6 %)/Ce 0.8 Zr 0.2 O 2 exhibited the best catalytic performance in all the cases studied, showing an even better behaviour than the noble metal reference Pt(1 %)/Al 2 O 3 under selected boundary conditions λ = 1.