Planar growth, facet-oriented La2O3 (003) in CuLa catalysts: Enhancement in charge transport and water adsorption for methanol steam reforming

Abstract

The dispersion of active components and the strong metal-support interactions (SMSI) are closely associated with the lifespans and activities of catalysts in methanol steam reforming (MSR). In this study, a copper-based (Cu-based) catalyst featuring a unique lamellar structure and (003) facet for lanthanum oxide (La₂O₃) was prepared by the molten salt impregnation method for the first time. Compared to the unmodified Cu/γ-Al₂O₃/Al catalyst, the lifetime was enhanced eightfold, reaching 150 h. La₂O₃ can lead to the formation of a fence structure, which enhances the dispersion of Cu through a domain-limiting effect. Additionally, the Cu atoms near the Cu(111)/La₂O₃(003) interface exhibit a higher degree of electron loss compared to La₂O₃ with polycrystalline facets. This characteristic contributes to the enhanced water adsorption and dissociation capacity of CuLa catalysts. These two factors lead to superior catalytic activity and lifespan of CuLa-2 h. This study offers insights into catalyst microstructure and green chemistry.