In the present catalyst, most pores had a diameter of smaller
than 15 nm (see Fig. 1), such a porous structure with high thermal stability showed a ‘‘confine effect’’ to prevent Ni particles from
sintering and crystalline growth, which was very important for the
catalytic stability towards CO2 reforming of CH4. H2-TPR of the
catalyst indicated a main reduction peak at 883 K with a shoulder
at 723 K (see Fig. 2) which could be attributed to the reduction of
NiO particles interacted strongly and weakly with ZrO2, respectively.
The large peak at the high temperature suggested that most
of the NiO in the catalyst interacted strongly with ZrO2 support.