What is the ruling on the following supplications: "O Allah, I ask You to distance me from sins," "O Allah, I ask You to keep me away from sins," and "O Allah, cure me of masturbation"?

Supplicating with what you supplicate is legislated, and conforming to the supplications of the Prophets, especially Prophet Muhammad, peace and blessings be upon him, is more blessed and comprehensive in meaning. Persistence, humility, and showing need and destitution before Allah are among the greatest causes for the answering of supplications.