Er steht auf der schwarzen Liste.

English Translation

He’s been blacklisted.

“Schwarzliste” (one word) seems to also be an option here: Schwarzliste – Schreibung, Synonyme, Beispiele | DWDS

But as far as I can tell, you can’t use it as a verb in German the same way you can in English: “we will blacklist you”, “you have been blacklisted”. I think this does not work in German: “wir schwarzlisten dich”, “du bist schwarzgelistet”. Instead, you use it as a noun in German and reword the sentence as clozemaster has done here: “he is on the blacklist” (“er steht auf der Schwarzliste” or “er steht auf der schwarzen Liste”).