Is it correct to term boron trifluoride a "catalyst" in electrophilic aromatic substitution?


> 
> In Friedel Craft Alkylation of aromatic compounds using $\ce{BF3}$ :
> 
> 
> 1. $\ce{BF3}$ acts as a lewis acid
> 2. It is used as a catalyst
> 3. Amount of $\ce{BF3}$ used in the reaction is almost equal to that of amount of benzene used.
> 4. $\ce{BF3}$ acts as a nucleophile.
> 
> 
> 


I am sure about options $1$ and $3$ being correct and $4$ th being incorrect but I am hesitant about option $2$.


*Catalyst is a substance that lowers the activation energy and enhances the rate of the reaction, in the end remaining unconsumed.*


Now, what **Lewis Acids** do is that they **make halogens stronger electrophiles by forming complexes with them**. Taking this further we can say that yes they serve as "catalysts" in the reaction because otherwise the reaction would have been lot slower.


However, the given answer is $1,3$. Is my reasoning correct and the answer wrong? **Is it functioning as a catalyst in the reaction?**




On the formal definition, I think $\ce{BF3}$ may fail the *remains unconsumed* part. It will form $\ce{[BF3X]-}$, which would need to revert to $\ce{BF3 + X^-}$ in order to complete the catalytic cycle. I don't think the $K\_\mathrm{d}$ of this complex is particularly high, so this is not likely to happen, hence it won't be a proper catalyst. This is also why you need a stoichiometric ammount of $\ce{BF3}$ for the reaction to proceed to completion.


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