Is it permissible to place a Mus'haf – open or closed – or hang Quranic plaques in a bedroom where intercourse takes place?

There is no harm in placing the Mus'haf (copy of the Qur'an) in a bedroom. However, it is recommended not to leave it open without reading, so it does not collect dust. As for hanging Quranic plaques, please refer to Fatwa no. 31553 regarding its ruling.