Yes, you can sell Ethereum to PayPal. However, there are a few things to keep in mind when doing so. First, PayPal does not currently support the direct purchase of cryptocurrency. This means that you will need to first sell your Ethereum for another currency (such as US dollars), and then use PayPal to send the US dollars to the buyer.
Secondly, PayPal has been known to freeze accounts that it suspects of being involved in cryptocurrency activity. So, if you are selling a large amount of Ethereum, it is best to do so in smaller increments over time to avoid having your account frozen. Finally, make sure that you are selling to a trusted buyer who has a good reputation on PayPal.