He dedicated most of his time to charity work.

他大部分时间都致力于慈善工作。

dedicate表示把时间或精力等用在...，用在哪方面就用介词to。 dedicate的名词是 dedication,表示对某事的热诚和献身。

her dedication to education她对教育的热诚付出。

He dedicated his life to science.

他献身于科学。