Is the word passed a noun?

No, the Word 'passed' is the past participle, past tense of the verb to pass.

The Word 'pass' is also a noun form; a Word for an act or instance of moving past or through something; a success in an examination, test, or course; a card, ticket, or permit giving authorization for the holder to enter or have access to a place; an act of kicking, hitting, or throwing the ball to another player on the same side.

The noun forms for the verb to pass are passer and the gerund, passing.