24 hours transit visa

Juan, there is no such a thing as 24 hours transit visa. There is 24 hour visa free transit and that is a status that will allow you to transit China visa free.

As far as your intention to exit the airport is concerned, your layover length is a borderline case. Chinese immigration authorities usually do not allow exist if the layover is shorter than 8 hours, so you are somewhere around that criterion. In other words, it is very hard to predict whether you will be granted a permit or not.

In any case, you are absolutely free to try to obtain a temporary entry permit by approaching 24/144 hour visa free transit counter immediately upon your landing where you will apply for a temporary entry permit by presenting your flight itinerary. After a short check an airport official will decide whether to grant you a permit or not. In any case, there are consequences of any kind even if the permit is not going to be granted. However, as I have written, you should try and I wish you the best of luck.