Bi-reforming of methane on Ni-based pyrochlore catalyst

• A Ni-based pyrochlore catalyst was synthesized using the modified Pechini method. In this method, 1 wt% Ni was doped into the La2Zr2O7 pyrochlore structure. The catalyst was characterized by H2-TPR, TPO, XRD, and EXAFS, and tested for its methane reforming activity under bi-reforming reaction conditions; i.e.; in the presence of CO2 and steam: 3CH4+CO2+2H2O⇌4CO+8H2 Repeated TPR/TPO cycles showed that the two consecutive TPR spectra do not change, showing that the catalyst is stable at high temperatures, and that the nickel oxidation/reduction process is reversible. The catalyst showed constant activity with time at all temperatures in the range of 700-950 °C over a cumulative period of 170 h. After this series of bi-reforming tests, TPO of the spent catalyst was carried out, which showed detectable but unquantifiable carbon deposition. The presence of steam in bi-reforming greatly limits carbon deposition compared to directly related dry-reforming tests on this same catalyst.

Ämnesord

NATURVETENSKAP  -- Kemi -- Fysikalisk kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Physical Chemistry (hsv//eng)

Nyckelord

Bi-reforming

Dry-reforming

Methane activation

Pyrochlore

Reforming

Syngas

Carbon dioxide

Catalyst activity

Catalysts

Deposition

Methane

Nickel

Reforming reactions

Dry reforming

Modified Pechini method

Pyrochlore structures

Pyrochlores

Reaction conditions

Reforming of methane

Syn-gas

Steam reforming

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