“Beneficent” is more related to good actions, while “benevolent” is more related to good character.
beneficent (adj.) = doing or producing good; especially related to charity
Ex: “They are a beneficent family who regularly volunteer at a homeless shelter.”
benevolent (adj.) = wishing others well; wanting good for others and to do good
Ex: “Despite his ugly appearance, the giant was benevolent and friendly.”