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Control of Thickness and Chemical Properties of Atomic Layer Deposition Overcoats for Stabilizing Cu/γ‐Al 2 O 3 Catalysts

2014; Wiley; Volume: 7; Issue: 12 Linguagem: Inglês

10.1002/cssc.201402832

1864-564X

Brandon J. O’Neill, Canan Sener, David H. K. Jackson, T. F. Kuech, James A. Dumesic,

Catalysis and Hydrodesulfurization Studies

Abstract Whereas sintering and leaching of copper nanoparticles during liquid‐phase catalytic processing can be prevented by using atomic layer deposition (ALD) to overcoat the nanoparticles with AlO x , this acidic overcoat leads to reversible deactivation of the catalyst by resinification and blocking of the pores within the overcoat during hydrogenation of furfural. We demonstrate that decreasing the overcoat thickness from 45 to 5 ALD cycles is an effective method to increase the rate per gram of catalyst and to decrease the rate of deactivation for catalysts pretreated at 673 K, and a fully regenerable copper catalyst can be produced with only five ALD cycles of AlO x . Moreover, although an overcoat of MgO x does not lead to stabilization of copper nanoparticles against sintering and leaching during liquid‐phase hydrogenation reactions, the AlO x overcoat can be chemically modified to decrease acidity and deactivation through the addition of MgO x , while maintaining stability of the copper nanoparticles.