Activity and Selectivity of a Nanostructured CuO/ZrO₂Catalyst in the Steam Reforming of Methanol

Abstract

Abstract:Steam reforming of methanol for production of hydrogen can be carried out over copper based catalyst. In the work presented here, the catalytic properties of a CuO/ZrO 2 catalyst (8.5 wt%) synthesised by a templating technique were investigated with respect to activity, long term stability, CO formation, and response to oxygen addition to the feed. The results were obtained using a fixed bed reactor and compared to a commercial methanol synthesis catalyst CuO/ZnO/Al 2 O 3 . It is shown that, depending on the time on stream, the temporary addition of oxygen to the feed has a beneficial effect on the activity of the CuO/ZrO 2 catalyst. After activation, the CuO/ZrO 2 catalyst is found to be more active ( per copper mass) than the CuO/ZnO/Al 2 O 3 system, more stable during time on stream ( measured up to 250 h), and to produce less CO. Structural characterisation by means of X-ray powder diffraction (XRD) and X-ray absorption spectroscopy (XAS) reveals that the catalyst (as prepared) consists of crystalline, tetragonal zirconia with small domain sizes ( about 60 Angstrom) and small/disordered crystallites of CuO.

In situ investigations of structure–activity relationships of a Cu/ZrO2 catalyst for the steam reforming of methanol

“…Subsequently, the feed of water and methanol for the steam reforming reaction (methanol : water, 2:1, see above for detailed concentrations) was introduced into the reactor and the catalyst was heated to 523 K at 6 K/min. In order to reveal the effect of a temporary oxidative treatment, [5,3] after 5 h time on stream 10 vol-% O 2 were added to the feed for about 30 min. In the second procedure the catalyst was reduced in a mixture of methanol and water (ratio 2:1, see above) at 523 K at a heating rate of 6 K/min.…”

“…[1,2] Improving the long-term stability, the hydrogen production rate, and the selectivity of suitable MSR catalysts are subjects of current research in heterogeneous catalysis. Recently, we presented a binary Cu/ZrO 2 catalyst which is more active compared to a commercial Cu/ZnO/Al 2 O 3 catalyst, more stable during time on stream, and produces less CO. [3] However, detailed structure-activity relationships of the Cu/ZrO 2 material are still lacking and shall be the subject of this work. Copper based materials have been extensively studied under MSR and methanol synthesis reaction conditions.…”

In situ study of the formation and stability of supported Pd2Ga methanol steam reforming catalysts

“…Cu-based catalysts are highly active and selective for methanol steam reforming [2,[6][7][8][9]. High selectivity to CO 2 and H 2 production is crucial due to the poisoning effect of CO on fuel cell anodes in polymer electrolyte membrane fuel cells (PEMFC), requiring <20 ppm CO in the H 2 fuel [10].…”

Methanol Steam Reforming

“…Accordingly, short addition of oxygen to a Cu/ZrO 2 MSR catalyst under working conditions was also shown to have an activating ef-fect on the Cu phase, which is even more pronounced and stable compared to Cu/ZnO [19,107]. In this case no significant lattice strain of Cu could be detected, but incorporation of oxygen in metal- …”