Q: Can I gift the reward of reciting the Qur'an to a deceased relative?
A: Any act of piety that is performed by a Muslim and then dedicated, either wholly or partially, to another Muslim, living or deceased, will receive the reward even if the nature of the reward is unknown. Such acts include (but not limited to) performing a voluntary Hajj, reciting the Qur'an, prayer, fasting, and charity. Imam Ahmad said that “every act of piety such as charity, prayer, etc. reaches the deceased according to what has been reported”.
Source: Sharh al-Muntaha & Kashshaf al-Qina’