Comparative study of Cu/ZnO catalysts derived from different precursors as a function of aging

Abstract

Structural modifications of Cu/ZnO catalysts for methanol steam reforming (MSR) as a function of precipitate aging in catalysts preparation process has been investigated comparatively. Freshly precipitated Cu,Zn-hydroxycarbonate (HC) and Cu,Zn-hydroxynitrate (HN) were aged in their mother liquor for a period of 120 min followed by washing, drying, calcination and reduction. Pronounced effect of aging was found for aged HC precipitates while no significant effect of aging was observed for aged HN solids. The bulk structure of the Cu/ZnO catalysts was investigated by means of TG/MS, in situ XRD and 63Cu NMR. The increase in the activity of the catalysts prepared by HC aging did not correlate linearly with the specific Cu surface area but coincides with an increase in the microstrain in the copper clusters presumably because of the improved interface between Cu and ZnO. Meanwhile, aging of HN precipitates results in large, separated and less strained Cu and ZnO particles with an inferior catalytic activity. Finally, both aged Cu/ZnO catalysts revealed smaller copper crystallite size compared to unaged samples

Selective Hydrogenolysis of Glycerol to Propylene Glycol on Cu–ZnO Composite Catalysts: Structural Requirements and Reaction Mechanism

“…[24][25][26] Günter et al reported that such strong interaction causes strained Cu lattices, and the Cu microstrain is closely related to the Cu-ZnO activities in methanol synthesis and methanol steam reforming. [26][27][28][29] It is apparent that this established knowledge will be beneficial to the current study of glycerol hydrogenolysis and the specific emphasis in this work on elucidating the structure effects on the performance of Cu-ZnO catalysts and the underlying reaction mechanism.…”

Hydrogen Production by Steam Reforming of Methanol over New Ag-Au(1-D)-CeO2 Catalyst

“…In the literature, copper based catalysts have received considerable attention for H 2 production by steam reforming of methanol (SRM) or oxidative steam reforming of methanol (OSRM) [3][4][5][6][7]. However, in recent times gold-base catalysts have been extensively studied in connection with the advancement in fuel cell technology and related hydrogen fuel processing.…”

Catalytic Partial Oxidation of Methanol over Copper–Zinc Based Catalysts: A Comparative Study of Alumina, Zirconia, and Magnesia as Promoters

“…Within 240-260°C, Cu/ZnO displayed higher H 2 selectivities (*60%) than Cu/Zn/Al 2 O 3 (*50%), Cu/Zn/MgO (*40%), and Cu/Zn/ZrO 2 (*40%). Presumably, Cu/ZnO and Cu/Zn/Al 2 O 3 might have a larger amount of active centers for SRM, which locate on the Cu-Zn interface [28,29], than other promoted catalysts for H 2 production. Cu/Zn/MgO appeared to have the same catalytic behavior as Cu/ZnO and Cu/Zn/Al 2 O 3 with a lower start-up temperature.…”