If you are doing personal branding already, you likely would not mind the ability to boost posts from your personal Facebook profile. It would allow you to reach more people outside of your network. However, posts from personal profiles can not be boosted – at least not directly. But, if you already own a Facebook page, there is actually an indirect way to do it.
After you have created a new post, click the share button, then choose share to page. After sharing the post to your page, simply click the boost button for the shared post, just as you would for normal page-posts.
Self-promotion like this, however, could come off as fake and narcissistic. Your real-life friends on Facebook might notice it and think it looks weird. If you don't have a line of work where this type of promotion makes sense, it could make it seem like you are just trying to attract unwarranted attention.
Should you boost your own posts?
Most "normal" people do not want to come off as narcissistic, so we spend a lot of energy and time, thinking about how other people might perceive something we are doing on social media. Often, this is either when promoting ourselves or our businesses. Some of us even hesitate to post a selfie.
There are just certain things, that people rarely seem to do, because they do not feel right about it. But, in general, I think it is fine to break the unwritten rules a little when it comes to advertising.
If you are strongly connected with your business or project, then it might make sense to make certain announcements from your personal profile, and then share them on the page representing your business.
As long as you are not doing anything fake, a little self-promotion is usually not a bad thing.