Thought experiment illustrated below:
Suppose a weird spacecraft entering Earth's atmosphere from low Earth orbit, payload first. Behind it there is an inverted nozzle shaped structure, attached with struts.
Let's assume everything is made out of some heat resistant material, except the blue coating inside the nozzle, which is made of ablative material sublimating.
Blue material expands into a gas trying to escape the nozzle, while air molecules compress it inside the nozzle.
Could this device produce thrust, reducing entry velocity?