致力 is a formal verb meaning 'to devote oneself to' or 'to dedicate oneself to'. It is commonly followed by the preposition 于 (yú) to introduce the goal or cause, as in 致力于 (zhì lì yú) + noun/verb phrase. Although marked as a verb-object compound (离合词), 致力 is not typically separated in modern Chinese; the object of devotion is expressed via 于, not inserted between the syllables. This word is used in formal or written contexts, such as academic or professional settings.