The phase transition from bimetallic catalyst to spinel phase can have a significant impact on the textural acidic properties of the catalyst. The textural acidic properties refer to the acidity of the catalyst surface, which is an important factor in determining its catalytic activity.

During the phase transition, the crystal structure of the catalyst changes from a bimetallic structure to a spinel structure. This can result in changes in the coordination and oxidation states of the metal ions, which can affect the acidic properties of the catalyst.

In general, spinel phases tend to have higher acidity compared to bimetallic phases, due to the presence of oxygen vacancies and/or cation vacancies in the crystal structure. These vacancies can create Lewis acid sites, which can interact with adsorbates and promote catalytic reactions.

However, the exact effect of the phase transition on the textural acidic properties of the catalyst will depend on various factors, such as the specific metals involved, the synthesis method, and the calcination temperature. For example, the size and distribution of the metal particles can also influence the textural acidic properties.

In summary, the phase transition from bimetallic catalyst to spinel phase can increase the textural acidic properties of the catalyst, but the magnitude of this effect will depend on the specific details of the system.